CN117188276A - Frequency and damping adjustable damper suitable for multi-mode high-frequency vibration control of sling and mounting method thereof - Google Patents

Abstract

The invention discloses a frequency and damping adjustable damper suitable for multi-mode high-frequency vibration control of a sling and an installation method thereof. The damper comprises a sling clamp and a tuning damping element, the tuning damping element comprises a steel strand clamp, steel strands and a mass block, and the steel strands are respectively provided with the mass block at two sides of the steel strand clamp. Each mass block is divided into a first mass block split body and a second mass block split body; the first mass block split body is provided with a U-shaped groove and is connected with the steel strand clamp through an anti-falling assembly; the second mass block is provided with a steel strand through hole and a lateral bolt hole; the steel strand passes through the steel strand through hole and is fixed by a lateral fixing bolt assembled in the lateral bolt hole; the depth of the U-shaped grooves provided on each mass is determined by the difference in the desired centroid position. Therefore, the invention solves the technical problems of difficult frequency and damping ratio adjustment of the traditional damper and can realize the efficient cooperative control of the multimode high-frequency vibration of the sling.

Description

Frequency and damping adjustable anti-vibration hammer for multi-modal high-frequency vibration control of slings and its installation method

Technical field

The present invention relates to the technical field of structural vibration control, and specifically relates to a frequency and damping adjustable anti-vibration hammer suitable for multi-mode high-frequency vibration control of slings and an installation method thereof.

Background technique

As the bridge structure with the strongest spanning capacity, the design and construction of suspension bridges have made great achievements in recent years, and their applications in the world's transportation field have become more extensive. As bridge spans continue to increase, the structural system becomes increasingly softer and wind-sensitive. As an important load-bearing component of a suspension bridge, long slings have the characteristics of low frequency, light weight, and small damping. They are typical wind-sensitive structures. They are prone to various harmful vibrations under wind loads. The vibration problem of long slings is that of large spans. One of the key issues in the design and operation and maintenance stages of suspension bridges. Frequent and large vibrations of the sling can easily cause fatigue of the sling and cause fatigue cracks at the joints of the cable and anchor, shortening the fatigue life of the sling. Large vibrations of the sling can easily cause cracking of the sling, causing corrosion of the sling and shortening its service life. . Excessive sling amplitude will also cause public panic and produce adverse social effects.

Tuned mass dampers (TMD) are increasingly used in structural vibration control. In addition to controlling the response of high-rise structures under the action of earthquakes, wind and other forces, they have also been proven to have good effects on the vibration response of long-span structures. vibration reduction effect. The existing anti-vibration hammer mainly fixes the mass block at both ends of the steel strand and uses the principle of TMD to achieve the purpose of sling vibration reduction. In order to achieve efficient control of high-frequency vibration of long slings in suspension bridges, Chinese Patent 2019101820975 (the name of the invention is: Multiple tuned mass dampers and sling vibration reduction method) and Chinese Patent 2020115079007 (the name of the invention is: A method for damping vibration of cable structures) The multi-directional multi-tuned mass dampers) all perform multi-modal vibration reduction control by installing multiple anti-vibration hammers on the slings. When the structure vibrates, the anti-vibration hammer suspended on it absorbs the vibration energy through relative motion, thereby reducing and eliminating the vibration of the wires. Various anti-vibration hammers have certain natural frequencies depending on their structure, weight, and geometric dimensions. However, existing anti-vibration hammers have difficulties in adjusting the frequency and damping ratio. Multiple vibration reduction devices need to be installed along the length of the sling. The vibration-absorbing device is prone to falling off and other risks, making it difficult to achieve long-term and efficient control of the multi-modal vibration of the sling.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a frequency and damping adjustable anti-vibration hammer suitable for multi-mode high-frequency vibration control of slings and an installation method thereof, so as to solve the problem of reducing the existing slings. It is difficult to adjust the frequency and damping of the vibration device, and the vibration reduction device is easy to fall off.

The present invention adopts the following technical solutions:

A frequency and damping adjustable anti-vibration hammer suitable for multi-modal high-frequency vibration control of slings, including a sling clamp (1) and a tuned damping element. The sling clamp (1) can be fixed on the sling (3) , the tuned damping elements include the steel strand clamp (5), the steel strand (11) and the mass block (7). The mass block (7) is installed on the steel strand (11), and the steel strand (11) passes through The steel strand clamp (5) is connected and fixed to the sling clamp (1); the tuning damping element is set as a tuning damping element with adjustable frequency and damping ratio, and among the tuning damping elements, the steel strand ( 11) A mass block (7) is installed on both sides of the steel strand clamp (5);

Each mass block (7) is arranged in a cylindrical shape as a whole and is divided into two sections, corresponding to the first and second mass block splits; the first mass block split is arranged close to the steel strand clamp (5) and A U-shaped groove is provided along the middle position, and the arms on both sides of the U-shaped groove are connected to the steel strand clamp (5) through the anti-fall component; the second mass block is separated and set away from the steel strand clamp (5), and The second mass block body is provided with a steel strand through hole (9) along the axis, and the second mass block body is provided with a lateral bolt hole (8) that penetrates the steel strand through hole (9);

The steel strand is set through the steel strand through hole (9) and fixed by the lateral fixing bolts assembled in the lateral bolt holes (8);

The depth of the U-shaped groove provided on each mass block (7) is determined according to the required center of mass position.

Preferably, the bending arc of the sling clamp (1) is consistent with the diameter of the sling (3), so that the two can be reliably fixed and ensure the stability of the tuning damping element.

Preferably, the sling clamp (1) and the steel strand clamp (5) are connected through a cover plate (4), and the rigidity of the cover plate (4) is sufficient to ensure that the sling clamp (1) and the steel strand clamp (5) Reliable fixation.

Preferably, the anti-fall component includes a steel wire, and two anti-fall holes (10) are provided on both sides of the U-shaped groove; one end of the steel wire is wound and fixed with the sling clamp (1), and the other end crosses the sling clamp (1). After the two anti-drop holes (10) are wound, they are fixed with the sling clamp.

Preferably, the mass of the mass block (7) and the distance between the mass block (7) and the steel strand clamp (5) are adjusted according to the actual vibration mode of the sling, so that the vibration frequency of the anti-vibration hammer is consistent with that of the sling. The vibration control frequency inside and outside the plane is suitable.

Preferably, according to the measured vibration mode of the sling, the steel strand (11) is wrapped with a damping coating to optimize the damping ratio design, so that the vibration mode damping ratio of the sling is greater than 0.5%.

Another technical purpose of the present invention is to provide an installation method of frequency and damping adjustable anti-vibration hammer suitable for multi-mode high-frequency vibration control of slings, which includes the following steps:

Step 1: Carry out long-term health monitoring of the slings that require vibration control, obtain the measured vibration data of the slings, and analyze the obtained measured vibration data of the slings to determine the actual vibration modes of the slings;

Step 2: Select the installation height of the anti-vibration hammer and the number of required tuned damping elements according to the number of vibration modes of the sling;

Step 3: Establish the characteristic equation of the sling-anti-vibration hammer coupling system, and calculate the additional modal damping ratio of the sling vibration mode;

Step 4: Use the particle swarm optimization algorithm to optimize the optimal frequency ratio and optimal damping ratio of each tuned damping element in the anti-vibration hammer, so that the additional modal damping ratio of the sling vibration mode is greater than 0.5%;

Step 5: Adjust the length of the steel strand between each tuned damping element and the steel strand clamp to adjust the frequency ratio of each tuned mass damper in place;

Step 6: Install the adjusted anti-vibration hammer on the sling to control the vibration of the sling;

Step 7. Check whether the anti-vibration hammer meets the vibration control requirements required by the sling after installation. If the inspection results show that the required vibration control requirements are not met, repeat steps 1 to 6 until the inspection results meet the vibration control requirements required by the sling. Require.

Beneficial effects:

The present invention sets the tuning damping element into an assembled structure (the mass block and the steel strand are detachably assembled and connected). Therefore, the installation position of each mass block and the steel strand can be adjusted according to the needs. The depth of the U-shaped groove on the mass block is set by different positions of the center of mass, thereby adjusting the frequency and damping ratio of the tuning damping element, thereby achieving efficient control of multi-modal high-frequency vibration of long slings in suspension bridges, and also achieving the sling surface Cooperative control of in-plane and out-of-plane multi-modal vibrations.

Specifically, the advantages of the anti-vibration hammer of the present invention over the prior art are reflected in:

(1) The anti-vibration hammer of the present invention is composed of four tuned damping elements with different frequencies and different damping ratios. Each tuned damping element has two tuning frequencies, which can directly realize the high efficiency of multi-modal high-frequency vibration of long slings in suspension bridges. control;

(2) The long sling vibration fully assembled adjustable anti-vibration hammer of the present invention has the same vibration frequency and damping ratio in all directions, and can realize coordinated control of the in-plane and out-of-plane multi-modal vibration of the sling;

(3) The frequency and damping ratio of the adjustable anti-vibration hammer of the multi-modal high-frequency vibration control of the sling of the present invention are continuously adjustable, which can realize the optimal control of the multi-modal high-frequency vibration of the sling and solve the traditional anti-vibration problem. The vibration hammer frequency and damping ratio cannot be adjusted;

(4) The installation process of the present invention is simple, the assembly requirements are low, the appearance of the bridge is basically not affected, and the manufacturing and installation costs of long sling protection measures are greatly reduced;

(5) The present invention has the advantages of high reliability, good durability, and obvious vibration reduction effect. It is particularly suitable for use in working environments where long slings require long fatigue life and are difficult to maintain, and has broad engineering application prospects.

Description of the drawings

Figure 1 is a schematic structural diagram of an adjustable anti-vibration hammer for multi-modal high-frequency vibration control of a sling;

Figure 2 is a schematic diagram of the sling clamp of the adjustable anti-vibration hammer;

Figure 3 is a schematic diagram of the cover of the adjustable anti-vibration hammer;

Figure 4 is a schematic diagram of the steel strand clamp with adjustable anti-vibration hammer;

Figure 5 is a schematic diagram of the mass block of the adjustable anti-vibration hammer;

Figure 6 is the workflow diagram of the adjustable anti-vibration hammer;

Reference signs:

1-sling clamp; 2-bolt port; 3-sling; 4-cover plate; 5-steel strand clamp; 6-steel strand reserved hole; 7-mass block; 8-lateral bolt hole; 9 - Steel strand through hole; 10 - Anti-drop hole; 11 - Steel strand; 12 - Lateral fixing bolt.

Detailed ways

In order to make the purpose and technical solutions of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

As shown in Figure 1, this embodiment provides a frequency and damping adjustable anti-vibration hammer suitable for multi-modal high-frequency vibration control of slings and its installation method, including a sling clamp 1, a bolt port 2, and a cover plate 4 , steel strand clamp 5, steel strand reserved hole 6, mass block 7, lateral bolt hole 8, steel strand through hole 9, anti-fall hole 10, steel strand 11, lateral fixing bolt 12.

The two parts of the sling clamp 1 described in this embodiment are combined on the sling and fixed through the fastening bolts at the first bolt holes 2a on both sides; the steel strand 11 passes through the steel strand clamp 5 Reserve holes 6 to fix the steel strand 11 through the anti-loosening bolts at the fifth bolt port 2e and the sixth bolt port 2f; the mass block 7 passes through the steel strand 11 through the steel strand through holes 9 respectively. , and fix it to both ends of the steel strand 11 through lateral fixing bolts 12; the steel strand clamp 5 is placed in a parallel position with the sling clamp, and the four third bolt holes 2c of the cover plate are Align with the second bolt port 2b of the sling clamp 1 and the fourth bolt port 2d of the steel strand clamp 5, and fix it with an anti-loosening self-locking bolt.

The steel strand 11 described in this embodiment adopts filled epoxy-coated steel strand, and the steel strand has no wire breakage after withstanding 2 million times of 0.45f _ptk ~ (0.45f _ptk -360MPa) cyclic load. After the fatigue test, perform a static strength tensile test on the steel strand, and the minimum tensile stress shall not be less than 0.95f _ptk .

The frequency and damping adjustable anti-vibration hammer described in this embodiment, which is suitable for multi-modal high-frequency vibration control of the sling, is installed at a position 2 m to 5 m away from the lower anchoring end of the sling.

The masses of the four mass blocks 7 described in this embodiment and the distance between the mass block 7 and the steel strand clamp 5 are adjusted according to the actual vibration mode of the sling, so that the vibration frequency of each damping element is consistent with that of the sling. The vibration control frequency inside and outside the plane is suitable.

According to the measured vibration mode of the sling, the four mass blocks 7 described in this embodiment wrap the steel strand 11 with water-based damping coatings of different thicknesses instead of the anti-corrosion coating to optimize the damping ratio design to make the sling vibrate. The modal damping ratio of the mode is greater than 0.5%.

As shown in Figure 2, the bending arc of the sling clamp 1 is consistent with the diameter of the sling, so that the two can be perfectly combined to ensure the stability of the tuning damping element.

As shown in Figure 3, the thickness of the cover plate 4 should be 2 mm ~ 3 mm and have high stiffness to ensure that the sling clamp 1 and the steel strand clamp 5 are reliably fixed.

As shown in Figure 4, the bending arc of the steel strand clamp 5 should be the diameter of the steel strand 11, so that the steel strand 11 can pass through smoothly and lock the steel strand through the anti-loosening self-locking bolts at the bolt ports 2e and 2f. Line 11 is fixed.

As shown in Figure 5, the mass of the mass block 7 is 5 ~ 10kg; the top of the mass block 7 has grooves of different depths according to the required center of mass position; a through hole is provided at the bottom to facilitate the steel stranding The wire passes through smoothly; holes are made on the side so that the mass block 7 passes through the steel strand 11 and is fixed with bolts; the mass block 7 is passed across the steel wire in the anti-fall hole 10 and the steel wire is wound On the sling clamp, prevent the mass block 7 from loosening and causing falling during the vibration of the sling.

As shown in Figure 6, the working steps of this embodiment are as follows:

① Carry out long-term health monitoring of slings that require vibration control, obtain measured vibration data of the slings, and analyze the data to determine the actual vibration modes of the slings;

② Select the optimal installation height of the anti-vibration hammer and the number of required tuned damping elements according to the number of modes of sling vibration;

③ Establish the characteristic equation of the sling-anti-vibration hammer coupling system to calculate the additional modal damping ratio of the sling vibration mode;

④ Use particle swarm optimization algorithm to optimize the optimal frequency ratio and optimal damping ratio of each tuned damping element in the anti-vibration hammer, so that the additional modal damping ratio of the sling vibration mode is greater than 0.5%;

⑤ Adjust the length of the steel strand between each tuned damping element and the steel strand clamp to adjust the frequency ratio of each tuned mass damper;

⑥ Install the adjusted anti-vibration hammer on the sling for vibration control;

⑦ Check whether the vibration reduction device meets the vibration control requirements required by the sling after installation.

The following aspects need to be noted in this embodiment:

1. All mass blocks and their attached fastening bolts in the vibration damping device should be inspected regularly to avoid looseness causing the mass block to slide. If necessary, welding can be performed after the bolts are tightened;

2. The distance between the mass block and the sling must be greater than the vibration amplitude of the mass block to avoid collision between the mass block and the sling;

3. When a set of damping devices is not enough to control all vibration modes of the sling, additional damping devices can be added along the length of the sling.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention. All substitutions are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (7)

1. A frequency and damping adjustable anti-vibration hammer suitable for multi-modal high-frequency vibration control of slings, including a sling clamp (1) and a tuned damping element. The sling clamp (1) can be fixed on the sling (3 ), the tuned damping element includes a steel strand clamp (5), a steel strand (11) and a mass block (7). The mass block (7) is installed on the steel strand (11), and the steel strand (11) The steel strand clamp (5) is connected and fixed with the sling clamp (1); it is characterized in that: the tuning damping element is set as an assembled tuning damping element with adjustable frequency and damping ratio, and the tuning damping Among the components, the steel strand (11) is equipped with a mass block (7) on both sides of the steel strand clamp (5); Each mass block (7) is arranged in a cylindrical shape as a whole and is divided into two sections, corresponding to the first and second mass block splits; the first mass block split is arranged close to the steel strand clamp (5) and A U-shaped groove is provided along the middle position, and the arms on both sides of the U-shaped groove are connected to the steel strand clamp (5) through the anti-fall component; the second mass block is separated and set away from the steel strand clamp (5), and The second mass block body is provided with a steel strand through hole (9) along the axis, and the second mass block body is provided with a lateral bolt hole (8) that penetrates the steel strand through hole (9); The steel strand is set through the steel strand through hole (9) and fixed by the lateral fixing bolts assembled in the lateral bolt holes (8); The depth of the U-shaped groove provided on each mass block (7) is determined according to the required center of mass position. 2. A frequency and damping adjustable anti-vibration hammer suitable for multi-mode high-frequency vibration control of slings according to claim 1, characterized in that: the bending arc of the sling clamp (1) is consistent with the sling (3 ) have the same diameter, so that the two can be reliably fixed to ensure the stability of the tuning damping element. 3. A frequency and damping adjustable anti-vibration hammer suitable for multi-mode high-frequency vibration control of slings according to claim 1, characterized in that: the sling clamp (1) and the steel strand clamp (5) They are connected through a cover plate (4), and the rigidity of the cover plate (4) is enough to ensure that the sling clamp (1) and the steel strand clamp (5) are reliably fixed. 4. The anti-vibration hammer with adjustable frequency and damping suitable for multi-mode high-frequency vibration control of slings according to claim 1, characterized in that: the anti-fall component includes a steel wire and two arms of a U-shaped groove There are two opposite anti-fall holes (10); one end of the steel wire is wound and fixed with the sling clamp (1), and the other end crosses the two anti-fall holes (10) and is wound and fixed with the sling clamp. 5. An anti-vibration hammer with adjustable frequency and damping suitable for multi-mode high-frequency vibration control of slings according to claim 1, characterized in that: the mass of the mass block (7) and the relationship between the mass block (7) and The distance between the steel strand clamps (5) is adjusted according to the actual vibration mode of the sling, so that the vibration frequency of the anti-vibration hammer adapts to the in-plane and in-plane vibration control frequency of the sling. 6. A frequency and damping adjustable anti-vibration hammer suitable for multi-modal high-frequency vibration control of slings according to claim 1, characterized in that: according to the measured vibration mode of the sling, the steel strand (11 ) The external wrapping damping coating optimizes the damping ratio design, thereby making the vibration mode damping ratio of the sling greater than 0.5%. 7. A method for installing an anti-vibration hammer with adjustable frequency and damping suitable for multi-modal high-frequency vibration control of slings according to claim 1, characterized in that it includes the following steps: Step 1: Carry out long-term health monitoring of the slings that require vibration control, obtain the measured vibration data of the slings, and analyze the obtained measured vibration data of the slings to determine the actual vibration modes of the slings; Step 2: Select the installation height of the anti-vibration hammer and the number of required tuned damping elements according to the number of vibration modes of the sling; Step 3: Establish the characteristic equation of the sling-anti-vibration hammer coupling system, and calculate the additional modal damping ratio of the sling vibration mode; Step 4: Use the particle swarm optimization algorithm to optimize the optimal frequency ratio and optimal damping ratio of each tuned damping element in the anti-vibration hammer, so that the additional modal damping ratio of the sling vibration mode is greater than 0.5%; Step 5: Adjust the length of the steel strand between each tuned damping element and the steel strand clamp to adjust the frequency ratio of each tuned mass damper in place; Step 6: Install the adjusted anti-vibration hammer on the sling to control the vibration of the sling; Step 7. Check whether the anti-vibration hammer meets the vibration control requirements required by the sling after installation. If the inspection results show that the required vibration control requirements are not met, repeat steps 1 to 6 until the inspection results meet the vibration control requirements required by the sling. Require.