Array tuned mass damper for double-cable multi-modal high-frequency vibration control and construction method thereof

Abstract

The application discloses an array type tuned mass damper suitable for double-sling multi-modal high-frequency vibration control and a construction method thereof. The array type tuned mass damper comprises a protective shell and a tuned damping element; the protective shell is fixed on a sling, and the tuned damping element is installed in the protective shell; the number of the tuned damping elements is several, and each tuned damping element is installed in the protective shell in an array distribution mode; each tuned damping element comprises a galvanized steel strand, a red copper mass block and a permanent magnet; the red copper mass block is suspended in the protective shell through the galvanized steel strand, and the permanent magnet is located directly below the red copper mass block and has a spacing with the red copper mass block, which meets the design requirement. Therefore, the array type tuned mass damper has a multi-frequency tuning effect, can realize simultaneous control of multi-modal in-plane and out-of-plane high-frequency vibration of double slings, and protects the tuned damping element through the protective shell, thereby improving the durability of the device.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of structural vibration control, and particularly relates to an array type tuned mass damper for double-cable multi-modal high-frequency vibration control of a suspension bridge and a construction method thereof. BACKGROUND

[0002] With the rapid development of modern transportation, the main span of suspension bridges continues to leap, and has gradually broken through from the kilometer level to the two-thousand-meter level. However, the long cable of a suspension bridge is a typical wind-sensitive component, and especially the parallel double-cable structural system, under complex wind environment, the parallel double cable of a long-span suspension bridge is prone to multi-modal in-phase high-frequency vibration. The multi-modal high-frequency vibration of the cable not only causes cable fatigue damage and shortens the fatigue life of the cable, but also causes huge social negative effects. Therefore, effective long-cable high-frequency vibration control technology is crucial for the safe service of the cable.

[0003] In order to effectively control the multi-modal high-frequency vibration of the long cable, the patents "Multiple tuned mass damper and cable vibration reduction method" and "Multi-directional multiple tuned mass damper for vibration reduction of a cable structure" achieve multi-modal vibration reduction control of the cable by installing multiple anti-vibration hammers on a single cable, but a single vibration reduction device can only control the vibration of one cable. For the parallel double-cable structural system, a vibration reduction device needs to be installed on each cable to control the vibration of the cable. In addition, it is difficult to adjust the frequency and damping ratio of the anti-vibration hammer, and it is difficult to achieve optimal control of the multi-modal vibration reduction of the cable. The patent "Multi-cable high-frequency vortex vibration reduction method and multiple tuned mass damper" uses a vibration reduction frame and a series of support rods to propose a multiple tuned mass damper with four main frequencies, but the vibration reduction system is too complex, the frequency and damping are difficult to adjust, and only the vibration of the cable within 4 modes can be effectively controlled. In order to control the multi-modal vibration of the cable, multiple vibration reduction devices need to be arranged along the length direction of the cable, increasing the risk of the vibration reduction device falling off. The paper "Cable damping vibration reduction technology of Nansha Bridge" proposes a damping vibration reduction system suitable for high-frequency vibration control of the cable, but the damper connection system is prone to fatigue problems when controlling the high-frequency vibration of the cable. SUMMARY

[0004] In view of the defects of the prior art, the purpose of the present application is to provide an array type tuned mass damper suitable for double-cable multi-modal high-frequency vibration control, to solve the problems of the existing cable vibration reduction device that the frequency and damping are difficult to adjust and cannot control the vibration of the double-cable simultaneously.

[0005] In order to achieve the above object, the present application adopts the following technical scheme: An array type tuned mass damper suitable for double sling multi-modal high frequency vibration control, comprising a protective shell and a tuned damping element; the protective shell is fixed on the sling, and the tuned damping element is installed in the protective shell; the number of the tuned damping elements is several, and each tuned damping element is installed in the protective shell in an array distribution mode; each tuned damping element comprises a galvanized steel wire, a red copper mass block and a permanent magnet group; the red copper mass block is suspended in the protective shell through the galvanized steel wire, and the permanent magnet group is located directly below the red copper mass block and has a spacing meeting the design requirement between the red copper mass block.

[0006] Preferably, the upper top plate of the protective shell is embedded with a hollow cylinder for each tuned damping element; the upper end of the galvanized steel wire is fixed with the hollow cylinder located above it, and the lower end is fixed with the red copper mass block.

[0007] Preferably, the red copper mass block is provided with a central hole along the central axis, the lower end of the galvanized steel wire penetrates into the central hole of the red copper mass block and is fixed with the red copper mass block, and the upper end of the galvanized steel wire penetrates through the hollow cylinder and is fixed with the hollow cylinder.

[0008] Preferably, the upper end of the galvanized steel wire is fixed with the hollow cylinder through a first bolt, and the lower end of the galvanized steel wire is fixed with the red copper mass block through a second bolt.

[0009] Preferably, the number of the tuned damping elements is the same as the number of the sling control modes; and the optimal frequency and damping ratio of each tuned damping element should make the modal damping ratio of the sling vibration mode greater than 0.5%.

[0010] Preferably, the mass of the red copper mass block of each tuned damping element is 5-10 kg.

[0011] Preferably, each tuned damping element is arranged in the protective shell in a row; among the tuned damping elements arranged in a row, the tuned damping element at the middle position is the middle tuned damping element, and the other tuned damping elements on both sides of the middle tuned damping element are side tuned damping elements; in addition, among the tuned damping elements arranged in a row, the frequency of the middle tuned damping element is the lowest, the frequency of the side tuned damping element increases with the increase of the distance of the side tuned damping element relative to the middle tuned damping element, the net spacing between adjacent two tuned damping elements is greater than 6 times the vibration displacement amplitude of the sling at the installation position of the protective shell, and the installation position of the protective shell on the sling is 2-5 m away from the lower anchoring end of the sling.

[0012] Preferably, the length of the galvanized steel wire between the copper mass and the upper top plate of the protective shell is adjusted by adjusting the first bolt to achieve the adjustment of the optimal frequency of each tuning damping element; the damping ratio of the tuning damping element is adjusted by adjusting the number or thickness of the permanent magnet group directly below the copper mass.

[0013] Preferably, the protective shell comprises a third bolt, a sling connecting clamp and a hollow box, the sling is between the end of the hollow box and the sling connecting clamp, and a matching hole is arranged between the end of the hollow box and the sling connecting clamp, and the connection and fixation of the end of the hollow box and the sling connecting clamp and the clamping of the sling between the end of the hollow box and the sling connecting clamp are achieved by assembling the third bolt in the matching hole.

[0014] Another technical purpose of the present application is to provide a construction method of the above-mentioned array type tuned mass damper suitable for double-sling multi-modal high-frequency vibration control, comprising the following steps: step one, measuring and analyzing the vibrating sling to determine the actual vibration mode of the sling, and selecting the installation height of the array type tuned mass damper and the number of tuned mass dampers required according to the number of sling vibration modes;

[0015] Step two, establishing the characteristic equation of the double-strand sling-array type tuned mass damper coupling system, and calculating the additional modal damping ratio of the sling vibration mode when the parameters of the array type tuned mass damper are certain;

[0016] Step three, using the particle swarm optimization algorithm to optimize the optimal frequency ratio and optimal damping ratio of each tuning damping element in the array type tuned mass damper, so that the additional modal damping ratio of the sling vibration mode is greater than or equal to 0.5%;

[0017] Step four, adjusting the length of the galvanized steel wire between the copper mass of the corresponding tuning damping element and the upper top plate of the protective shell by the first bolt to achieve the adjustment of the frequency ratio of each tuned mass damper;

[0018] Step five, adjusting the number of permanent magnet groups at the bottom of the copper mass to achieve the optimal damping ratio adjustment of each tuned mass damper;

[0019] Step six, installing the adjusted array type tuned mass damper on the sling through the third bolt and the sling connecting clamp.

[0020] The beneficial effects of the present application are:

[0021] 1. The array type tuned mass damper of the present application is composed of multiple tuning damping elements with different frequencies and different damping ratios, and can directly realize double-sling multi-modal high-frequency vibration control;

[0022] 2. The array-type tuned mass damper of the present invention has the same vibration frequency and damping ratio in all directions, which can control the vibration of the sling in all directions;

[0023] 3. The frequency and damping ratio of the array-type tuned mass damper of the present invention are continuously adjustable, which can realize the optimal control of multi-mode high-frequency vibration of the sling;

[0024] 4. The appearance of this invention is similar to that of a vibration damping frame, so it has little impact on the appearance of the bridge. At the same time, it occupies little space and is easy to integrate and install. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of an array-type tuned mass damper suitable for multimodal high-frequency vibration control of dual-sling systems. Figure 2 A schematic diagram of the structure of the protective housing for an array-type tuned mass damper;

[0026] Figure 3 The overall appearance of the sling for installing the array-type tuned mass damper;

[0027] The numbers in the diagram represent the following: 1. Protective shell, 101. Third bolt, 102. Sling connection clamp, 103. Hollow box, 2. First bolt, 3. Hollow cylinder, 4. Tuning damping element, 5. Galvanized steel strand, 6. Copper mass block, 7. Second bolt, 8. Permanent magnet assembly, 9. Sling. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0029] like Figure 1 As shown, an array-type tuned mass damper suitable for multimodal high-frequency vibration control of dual-slings in this embodiment includes a protective shell 1, a first bolt 2, a hollow cylinder 3, a tuned damping element 4, a galvanized steel strand 5, a copper mass block 6, a bolt 7, and a permanent magnet assembly 8.

[0030] The protective housing 1 described in this embodiment includes a third bolt 101, a sling connection clamp 102, and a hollow box 103. The protective housing 1 is fixed to the sling 9 by the third bolt 101 and the sling connection clamp 102. The hollow cylinder 3 is embedded in the upper top plate of the protective housing 1. The tuning damping element 4 includes a galvanized steel strand 5 and a copper mass block 6. A hole is drilled in the center of the copper mass block 6. The galvanized steel strand 5 passes through the center hole of the copper mass block and is fixed to the copper mass block by a second bolt 7. The upper end of the galvanized steel strand of the tuning damping element 4 passes through the hollow cylinder 3 and is fixed to the hollow cylinder 3 by a first bolt 2. The permanent magnet assembly 8 is installed on the upper side of the lower bottom plate of the protective housing.

[0031] The array type tuned mass damper for double sling multi-modal high frequency vibration control described in the embodiment should be installed at a position 2-5 m away from the lower anchoring end of the sling, the number of the tuned damping elements 4 is the same as the number of the sling control modes, the mass of the red copper mass block 6 of the tuned damping element is 5-10 kg, the frequency and damping ratio of each tuned damping element are optimized and designed according to the measured vibration mode of the sling, and the modal damping ratio of the sling vibration mode should be greater than 0.5%.

[0032] The optimal frequency of the tuned damping element 4 described in the embodiment can be adjusted by adjusting the length of the galvanized steel wire between the red copper mass block 6 and the top plate of the protective shell 1 through the first bolt 2. The tuned damping element with the lowest frequency is located at the center position of the protective shell 1, and the other tuned damping elements are arranged to the left and right of the central tuned damping element in sequence as the frequency increases. The net spacing of the tuned damping elements should be greater than 6 times the amplitude of the sling vibration displacement at the damper installation position.

[0033] The red copper mass block 6 of the tuned damping element 4 described in the embodiment generates an eddy current damping effect when it cuts the magnetic induction lines generated by the permanent magnet group 8. The optimal damping ratio adjustment of the tuned damping element damping ratio is achieved by adjusting the thickness of the permanent magnet group below the mass block.

[0034] The working steps of the embodiment are as follows:

[0035] ① The actual vibration mode of the sling is determined by performing measurement analysis on the sling in vibration, and the installation height of the array type tuned mass damper and the number of tuned mass dampers required are selected according to the number of sling vibration modes;

[0036] ② The characteristic equation of the double strand sling-array type tuned mass damper coupling system is established, and when the array type tuned mass damper parameters are certain, the additional modal damping ratio of the sling vibration mode is calculated;

[0037] ③ The optimal frequency ratio and optimal damping ratio of each tuned damping element in the array type tuned mass damper are optimized by using particle swarm optimization algorithm and the like, so that the additional modal damping ratio of the sling vibration mode is greater than 0.5%;

[0038] ④ The length of the galvanized steel wire between the red copper mass block 6 of each tuned damping element and the top plate of the protective shell 1 is adjusted by the first bolt 2 to realize the adjustment of the frequency ratio of each tuned mass damper;

[0039] ⑤ The number of the permanent magnet group 8 at the bottom of the red copper mass block 6 is adjusted to realize the optimal damping ratio adjustment of each tuned mass damper;

[0040] 6. The array type tuned mass damper is installed on the sling through the third bolt 101 and the sling connecting clamp 102;

[0041] The working principle of the embodiment is as follows:

[0042] The array type tuned mass damper is installed on the sling 9 at a predetermined position, when the sling 9 vibrates, the vibration of the sling will drive each tuned mass damper element of the array type tuned mass damper to vibrate, the vibration of each damper will produce an additional damping effect on the sling, which can obviously reduce the vibration of the sling, in addition, since the vibration direction of the sling is opposite to the vibration direction of the tuned mass damper element 4, the control force generated by the tuned mass damper can further reduce the vibration of the sling.

[0043] In the embodiment, the following aspects need to be paid attention to:

[0044] I. The installation position of the permanent magnet group should be provided with a groove matched with the size of the permanent magnet group, so as to facilitate the installation of the permanent magnet group;

[0045] II. The static spacing of each tuned mass damper should be greater than the vibration amplitude of the mass block, so as to avoid collision of the mass block;

[0046] III. When the installation space is insufficient, a plurality of vibration reduction devices can be arranged along the length direction of the sling;

[0047] The technical means disclosed in the present application is not limited to the technical means disclosed in the above embodiment, but also includes the technical solutions composed of any combination of the above technical features.

Claims

1. An array-type tuned mass damper suitable for multimodal high-frequency vibration control of a dual-sling cable, comprising a protective housing (1) and a tuned damping element (4); the protective housing (1) is fixed on the sling (9), and the tuned damping element (4) is installed in the protective housing (1); characterized in that: The number of the tuned damping elements (4) is several, and each tuned damping element (4) is installed in the protective housing (1) in an array distribution; Each tuned damping element (4) includes a galvanized steel strand (5), a copper mass block (6), and a permanent magnet assembly (8); the copper mass block (6) is suspended in the protective housing (1) by the galvanized steel strand (5), and the permanent magnet assembly (8) is located directly below the copper mass block (6) and there is a distance between it and the copper mass block (6) that meets the design requirements; Each tuned damping element (4) is arranged in a row in the protective housing (1); Among the various tuned damping elements (4) arranged in a row, the tuned damping element in the middle position is the middle tuned damping element, while the other tuned damping elements on both sides of the middle tuned damping element are the side tuned damping elements. In addition, among the various tuned damping elements (4) arranged in a row, the middle tuned damping element has the lowest frequency, while the frequency of the side tuned damping elements increases with the increase of their distance relative to the middle tuned damping element. At the same time, the net distance between two adjacent tuned damping elements is greater than 6 times the vibration displacement amplitude of the sling at the installation position of the protective shell (1). The distance between the installation position of the protective shell (1) on the sling (9) and the lower anchoring end of the sling (9) is 2~5m.

2. The array-type tuned mass damper for multi-mode high-frequency vibration control of dual-slings according to claim 1, characterized in that: The top plate of the protective shell (1) has a hollow cylinder (3) embedded in each tuning damping element (4); the upper end of the galvanized steel strand (5) is fixed to the hollow cylinder (3) above it, while the lower end is fixed to the copper mass block (6).

3. The array-type tuned mass damper for multi-mode high-frequency vibration control of dual-slings according to claim 1, characterized in that: The copper mass block (6) has a central hole along its central axis. The lower end of the galvanized steel strand (5) passes through the central hole of the copper mass block (6) and is fixed to the copper mass block (6). The upper end of the galvanized steel strand (5) passes through the hollow cylinder (3) and is fixed to the hollow cylinder (3).

4. The array-type tuned mass damper for multi-mode high-frequency vibration control of dual-sling systems according to claim 3, characterized in that: The upper end of the galvanized steel strand (5) is fixed to the hollow cylinder (3) by the first bolt (2), while the lower end of the galvanized steel strand (5) is fixed to the copper mass block (6) by the second bolt (7).

5. The array-type tuned mass damper for multi-mode high-frequency vibration control of dual-sling systems according to claim 4, characterized in that: The number of the tuned damping elements (4) is the same as the number of the sling control modes; and the optimal frequency and damping ratio of each tuned damping element should make the modal damping ratio of the sling vibration mode greater than 0.5%.

6. The array-type tuned mass damper for multi-mode high-frequency vibration control of dual-slings according to claim 5, characterized in that: The mass of the copper mass block (6) of each tuned damping element is 5 ~ 10 kg.

7. The array-type tuned mass damper for multi-mode high-frequency vibration control of dual-sling systems according to claim 6, characterized in that: The length of the galvanized steel strand (5) between the copper mass block (6) and the top plate of the protective shell (1) is adjusted by adjusting the first bolt (2) to achieve the optimal frequency adjustment of each tuning damping element (4); The damping ratio of the tuning damping element (4) can be adjusted by adjusting the number or thickness of the permanent magnet group (8) directly below the copper mass block (6).

8. The array-type tuned mass damper for multi-mode high-frequency vibration control of dual-slings according to claim 7, characterized in that: The protective shell (1) includes a third bolt (101), a sling connection clamp (102), and a hollow box (103). The sling (9) is located between the end of the hollow box (103) and the sling connection clamp (102). A matching hole is provided between the end of the hollow box (103) and the sling connection clamp (102). By assembling the third bolt (101) in the matching hole, the connection and fixation between the end of the hollow box (103) and the sling connection clamp (102) are realized, and the sling (9) located between the end of the hollow box (103) and the sling connection clamp (102) is clamped.

9. A construction method for an array-type tuned mass damper suitable for multi-mode high-frequency vibration control of a dual-sling cable, as described in claim 1, characterized in that, The steps include: Step 1: Conduct on-site measurement and analysis of the vibrating sling to determine the actual vibration mode of the sling, and select the installation height of the array-type tuned mass damper and the required number of tuned mass dampers based on the number of vibration modes of the sling; Step 2: Establish the characteristic equation of the double-strand suspender-array tuned mass damper coupled system. When the parameters of the array tuned mass damper are fixed, calculate the additional modal damping ratio of the suspender vibration mode. Step 3: Using the particle swarm optimization algorithm, optimize the optimal frequency ratio and optimal damping ratio of each tuned damping element in the array-type tuned mass damper, so that the additional modal damping ratio of the cable vibration mode is greater than or equal to 0.5%; Step 4: Use the first bolt to adjust the length of the galvanized steel strand between the copper mass block of the corresponding tuning damping element and the top plate of the protective shell to adjust the frequency ratio of each tuning mass damper. Step 5: Adjust the number of permanent magnet groups at the bottom of the copper mass block to achieve the optimal damping ratio adjustment of each tuned mass damper; Step 6: Install the adjusted array-type tuned mass damper onto the sling using the third bolt and sling connection clamp.

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