Low-frequency tuned mass damping device

Abstract

The utility model belongs to the field of low-frequency vibration control, and provides a low-frequency tuned mass damping device. The spring and the functional element with sufficient strength and local overall rigidity close to zero are combined for use to share the gravity of the vibrator together, so that the problems of overlarge spring deformation and insufficient controlled structure space of a traditional tuned mass damping device under a low-frequency condition are solved. The functional element provides stable tension during vibration, so that the vibrator is larger in mass, and the spring is shorter and lighter. And compared with an inerter device, the inertia force is larger, the required system damping is higher, and the vibration control efficiency is higher. Functional elements are bilaterally and symmetrically tensioned, and high-strength thin ropes and large-diameter turntables are introduced, so that the friction energy consumption can be greatly reduced, the system damping is ensured to meet optimization conditions, and the vibration control efficiency is ensured. The vertical low-frequency vibration control device has remarkable advantages in the field of low-frequency vibration control, and can be used for vertical low-frequency vibration control of various large-scale structures.

Description

Technical Field

[0001] The utility model belongs to the technical field of low-frequency vibration control, and relates to a low-frequency tuned mass damper, in particular to a tuned mass damper for controlling the vertical low-frequency vortex-induced vibration of long-span bridges. Background Technique

[0002] The spans of modern bridges are increasing continuously. The main spans of many bridges exceed 1000 meters, and their vertical vibration frequencies may be lower than 0.2 Hz. The vertical vortex-induced vibration of long-span bridges occurs frequently and needs to be suppressed to ensure the safety of the bridges and vehicle driving. Bridges do not experience lateral vortex-induced vibration, and torsional vortex-induced vibration is also very rare. Therefore, the present utility model mainly focuses on the problem of vertical vortex-induced vibration of bridges. Tuned mass dampers have been applied to the control of higher-frequency vertical vortex-induced vibration of many bridges. However, when the bridge vibration frequency is lower than 0.2 Hz, traditional tuned mass dampers face challenges such as excessive spring stretching or compression (g / (2πf) 2 , where g and f are the gravitational acceleration and vibration frequency respectively) and insufficient internal space of the bridge. For example, the static deformation of the spring required for a frequency of 0.2 Hz is about 6.25 meters, while the height of a typical bridge box girder is usually in the range of 3.0 - 4.5 m, which makes it difficult for traditional tuned mass dampers to be used for the control of low-frequency (<0.2 Hz) vertical vortex-induced vibration of long-span bridges. The lower the frequency, the more turns are required, the longer the spring is, and the greater the mass is. The spring needs to bear its own weight, so there is an upper limit to the number of its turns.

[0003] In order to reduce the frequency, a tuned mass-inerter damper introduces an inerter element with a large equivalent mass and a small physical mass (the ratio of the equivalent mass provided by it to the physical mass can reach dozens, hundreds, or even larger). Thus, under the condition of ensuring the same frequency, the allowable stiffness of the spring can be greatly improved, thereby reducing the number of turns of the spring and the static deformation of the spring, and the required vertical space is also greatly reduced, finally making it possible to control the low-frequency vertical vortex-induced vibration on long-span bridges. However, during the vibration process of the tuned mass-inerter damper, the inerter element does not generate inertial force, only the oscillator suspended by the spring vibrates to generate inertial force, and it is required to drive the entire system to vibrate. Therefore, the amplitude of the oscillator is small, and the vibration control efficiency is low.

[0004] The introduction of the inerter mass avoids the problem of excessive static deformation of the spring in low-frequency situations to a certain extent and theoretically can achieve any low frequency. However, due to the introduction of a very large inerter equivalent mass (several times or even more than a dozen times the mass of the oscillator), the proportion of the oscillator mass is small, and the inertial force that can be generated to drive the system to vibrate is also small, similar to "a small horse pulling a big cart", so the vibration control efficiency is low.

[0005] In view of the deficiencies of traditional tuned mass dampers and tuned mass inerter dampers, it is necessary to develop a more efficient and practical damping device. A part of the gravity of the oscillator of this device is borne by the spring, and the rest (the larger part) of the gravity is borne by other functional elements with sufficient bearing capacity and deformation ability and close to zero stiffness. Therefore, the same spring as that of the traditional tuned mass damper can be used, and a larger physical mass of the oscillator can be adopted (equivalent to the sum of the physical mass (a small part) of the oscillator of the tuned mass inerter damper and the equivalent mass of the inerter (the larger part)). The physical mass of the oscillator of the new device can be several times or even more than ten times that of the oscillators of traditional tuned mass dampers and tuned mass inerter dampers, and the inertial force that can be generated also basically changes linearly with the mass of the oscillator. Therefore, the amplitude and vibration control efficiency of the device are greatly improved. Summary of the Invention

[0006] The present invention provides a low-frequency tuned mass damping device, which solves the problem of controlling the vertical low-frequency vortex-induced vibration of long-span bridges. The gravity of the oscillator of the damping device is jointly borne by the spring and a functional element that meets the specified requirements of force and deformation, and the sharing ratio can be set as required. This functional element can withstand the required tensile or compressive force in the working state, but its tensile and compressive stiffness is very small and close to zero within a relatively long local displacement working range, and its force-displacement curve is in the form of Figure 2 as shown. The most ideal case is the typical curve one, but the actual material is generally not so ideal, and it is generally in the form of typical curve two and typical curve three. By combining different areas, lengths, and forces of materials with force-displacement typical curves two and three, a force-displacement curve basically similar to that of typical curve one can be achieved. During the vibration of the oscillator, all the mass of the oscillator generates inertial force, and the inertial force is borne by the spring, while the tensile or compressive force borne by the functional element remains basically unchanged throughout the vibration process.

[0007] Technical solution of the present invention:

[0008] A low-frequency tuned mass damping device includes a spring 1, an oscillator 2, a damper 3, a bearing seat 4, bearings 5, a rotating shaft 6, a turntable 7, a high-strength thin rope 8, a functional element 9, and a rubber plate 10. Taking the tension of the spring 2 and the functional element 9 as an example, the upper end of the spring 1 is suspended on the top plate of the bridge main girder or the built-in support in the main girder, and the lower end suspends the oscillator 2. One end of the damper 3 is connected to the oscillator 2, and the other end is connected to the main girder or the built-in support. The spring 1, the oscillator 2, and the damper 3 form a traditional tuned mass damping device. The bearing seats 4 (at least two and with sufficient distance) are installed on the bridge top plate or the built-in support, the bearings 5 (at least two) are installed in the bearing seats 4, the rotating shaft 6 passes through the bearings 5, the turntable 7 is fixedly sleeved at a suitable position on the rotating shaft 6, the high-strength thin rope 8 is wound around the turntable 7 for about 1 / 4 turn or more than one turn, the lower end suspends the oscillator 2, and the other end is connected to the horizontally or obliquely arranged tensioned functional elements 9 arranged symmetrically on the left and right. The functional elements 9 are fixed at suitable positions inside the main girder or the built-in support. The tensioned functional elements 9 provide vertical tension for the oscillator 2, thereby reducing the tension of the spring 1 under the condition of the static equilibrium state of the oscillator 2. The strength requirement of the spring 1 can be greatly reduced, and thus a thinner wire diameter, fewer turns, and a smaller original length can be adopted. During the vibration process of the system, the vertical tension provided by the functional elements 9 for the oscillator 2 remains basically unchanged. All the inertial forces generated by the vibration of the oscillator 2 are borne by the spring 1. Therefore, the amplitude is relatively larger than that of the oscillator of the inertance damper, and the generated damping force is larger, and the vibration control effect is better. Under the condition of the same mass static equilibrium state of the oscillator 2, the proportion of the spring 1 and the functional element 9 sharing the gravity of the oscillator 2 in the vertical direction can be flexibly set as required, and the parameters such as the model, number of turns, and stiffness of the spring 1 can be adjusted within a large range accordingly. In order to avoid adverse effects on the spring 1 and the functional element 9 caused by excessive amplitude of the oscillator 2, a high-damping rubber plate 10 is arranged on the bottom plate of the main girder to limit the amplitude of the oscillator 2. If the two collide, it can also consume the energy of the system and suppress the vibration. The distance between the oscillator 2 in the static equilibrium state and the rubber plate 10 is optimized according to needs.

[0009] It is also possible to adopt the scheme of the spring 2 being compressed and the functional element 9 being compressed, which will not be elaborated here. Although the scheme of the functional element 9 being compressed is theoretically possible, its adaptability is poor and it is difficult to adopt.

[0010] Advantages of the present utility model: (1) By jointly bearing the gravity of the oscillator with the spring and the functional element, the problems of excessive spring deformation and limited internal space of the bridge under low-frequency conditions in traditional tuned mass dampers are avoided; (2) Compared with traditional tuned mass inerter dampers, for the same spring 1, an oscillator with a larger mass can be adopted to generate a larger inertial force. Since it is not necessary to drive the inerter mass to vibrate, the amplitude of the oscillator is larger, and the generated damping force is larger, significantly improving the vibration control efficiency; (3) By adopting a high-strength thin rope and a rotating shaft turntable structure, the functional element does not directly participate in the stretching and contracting during vibration, reducing friction and energy consumption, creating conditions to ensure that the system damping meets the optimal requirements; (4) By adopting a large-diameter turntable and a small-diameter rotating shaft, under the condition of meeting the up-and-down vibration requirements of the oscillator 2, the rotation angle and frictional energy consumption of the bearing 5 are minimized as much as possible, creating conditions to ensure that the system damping meets the optimal requirements; (5) The rubber plate provides protection under extreme amplitude conditions, avoiding damage to the system caused by excessive amplitude, and ensuring the stability and durability of the system. Description of the Drawings

[0011] Figure 1 is a low-frequency tuned mass damping device;

[0012] Figure 2 is the force-displacement curve of the functional element;

[0013] Figure 3 is a partial schematic diagram of the rotating shaft and the turntable.

[0014] In the figure: 1 spring, 2 oscillator, 3 damper, 4 bearing seat, 5 bearing, 6 rotating shaft, 7 turntable, 8 high-strength thin rope, 9 functional element, 10 rubber plate. Detailed Embodiment

[0015] The following combines the technical solutions and the drawings to describe in detail the specific embodiments of the present utility model.

[0016] As Figure 1As shown in the figure, a low-frequency tuned mass damping device is provided, which includes a spring 1, an oscillator 2, a damper 3, a bearing seat 4, a bearing 5, a rotating shaft 6, a turntable 7, a high-strength thin rope 8, a functional element 9, and a rubber plate 10. Taking the spring 2 and the functional element 9 being in tension as an example, the technical solution is introduced as follows: The upper end of the spring 1 is suspended on the top plate of the bridge main girder or the built-in support of the main girder, and the lower end suspends the oscillator 2. One end of the damper 3 is connected to the oscillator 2, and the other end is connected to the main girder or the built-in support. The spring 1, the oscillator 2, and the damper 3 form a traditional tuned mass damping device. The bearing seats 4 (at least two and with sufficient distance) are installed on the bridge top plate or the built-in support. The bearings 5 (at least two) are installed in the bearing seats 4. The rotating shaft 6 passes through the bearings 5. The turntable 7 is fixedly sleeved at a suitable position on the rotating shaft 6. The high-strength thin rope 8 is wound around the turntable 7 for about 1 / 4 week or more than one week, and the lower end suspends the oscillator 2, and the other end is connected to the horizontally or obliquely arranged tensioned functional elements 9 that are symmetrically arranged on the left and right. The functional elements 9 are fixed at suitable positions inside the main girder or the built-in support. The tensioned functional elements 9 provide vertical tension for the oscillator 2. In order to prevent the excessive amplitude of the oscillator 2 from having an adverse impact on the spring 1 and the functional element 9, a high-damping rubber plate 10 is provided on the bottom plate of the main girder to limit the amplitude of the oscillator 2. If the two collide, it can also consume the energy of the system and suppress vibration.

[0017] The material of the described spring 1 should have sufficient strength, stable stiffness, and good durability. The specific dimensions, specifications, materials, and quantities are not limited.

[0018] The described oscillator 2 meets the quality requirements. The specific dimensions and materials are not limited. It is recommended to use an anti-rust steel plate, which has a large density and a small volume, saves space, and has stable quality.

[0019] The described damper 3 can provide stable damping according to the difference between the optimal damping required by the system and the self-damping of the device, ensuring that the vibration system basically reaches the theoretical optimal damping, thereby achieving near-optimal control efficiency, and having good economy and durability. The specific models, specifications, and quantities are not limited.

[0020] The described bearing seat 4 should have sufficient strength and stiffness, and the position and direction are convenient for fine adjustment to ensure that the rotating shaft 6 drives the bearing 5 to have as small a friction force as possible during rotation. The specific materials, specifications, and structural forms are not limited.

[0021] The described bearing 5 has sufficient strength and stiffness, a friction coefficient as small as possible, and an inner diameter matching the diameter of the rotating shaft 6. The specific specifications are not limited.

[0022] The described rotating shaft 6 has sufficient strength and stiffness, and is as light as possible to reduce the friction force of the bearing 5.

[0023] The described turntable 7 has sufficient strength and stiffness and is as lightweight as possible to reduce the frictional force of the bearing 5. The ratio of the turntable diameter to the shaft diameter is designed according to requirements. The larger the ratio, the smaller the rotation angle of the shaft 6 and the less energy consumption, thus ensuring that the requirements for the optimal damping ratio of the system are met.

[0024] In addition to the damper 3, the main damping of the vibration system comes from the rotational friction energy consumption of the bearing 5. If the combination of the friction coefficient of the bearing 5 and the ratio of the turntable 7 to the shaft diameter is appropriate, the basic optimal damping ratio (7%-8%) required by the system can be achieved, and the damper 3 can be omitted, saving costs.

[0025] The described high-strength and thin rope 8 should have sufficient strength and stiffness, and the material, form, and size are not limited.

[0026] The described functional element 9 should have sufficient strength, large deformation ability, and a sufficiently wide and stable force-displacement flat section characteristic. The material, size, specifications, etc. are not limited. The high-strength and thin rope 8 at the connection section with the oscillator 2 and the turntable 7 can also be replaced by the functional element 9. Since the lateral space of the main beam is not limited, the functional element 9 arranged horizontally or obliquely can have a sufficient length to meet the requirements. Therefore, the high-strength and thin rope 8 in this section generally does not use the functional element 9, and the transmission connection is more convenient.

[0027] If the strength of the functional element 9, the force-displacement curve, the vertical space height of the main beam, etc. meet the requirements of the vibration frequency and amplitude, the functional element 9 can also directly suspend the oscillator 2 like the spring 1, omitting the bearing seat 4, the bearing 5, the shaft 6, and the turntable 7, and the structure is simpler. However, for the actual bridge main beam, the internal vertical space height is only 3.0 - 4.5 meters. Considering the thickness of the oscillator itself and the amplitude of the oscillator, about 1 meter needs to be reserved. The available original length and static elongation space for the functional element 9 are only 2.0 - 3.5 meters. The ratio range of the available deformation displacement of the functional element 9 to the original length is generally in the interval of 0.05 - 0.15 (too large displacement, unstable performance). Considering the maximum tensile length of 1 meter, the required original length is in the range of 6.7 - 20m. Even considering the maximum tensile length of 0.5 meter, the required original length is in the range of 3.3 - 10m. Therefore, only when the functional element 9 has a sufficiently wide available deformation range and a relatively small tensile length required for vibration control (such as <0.2m), can the device be simplified. If the functional element 9 directly suspends the oscillator 2 vertically, the system damping is smaller and it is easier to meet the requirements for the optimal damping ratio.

[0028] The advantages of adopting the foregoing solution with the bearing seat 4, bearing 5, rotating shaft 6, turntable 7, and high-strength thin rope 8 are that the length of the functional element 9 is basically not limited, and the performance requirements for the functional element 9 are also significantly reduced. The left-right symmetric arrangement of the functional element 9 can offset the horizontal force acting on the bearing 6, thereby reducing the friction of the bearing and the damping of the system, and also significantly reducing the strength and stiffness requirements for the bearing seat 4. The reason for adopting a large-diameter turntable and a small-diameter rotating shaft is to minimize the rotation angle of the bearing 5 under the condition of meeting the vertical vibration amplitude of the oscillator, thereby reducing energy consumption and ensuring that the system damping is not higher than the optimal damping.

[0029] During the up-and-down vibration of the oscillator 2, the high-strength thin rope 8 is respectively wound or unwound clockwise or counterclockwise around the turntable 7, with basically no energy consumption. If there is no high-strength thin rope 8 and the functional element 9 is directly wound around the turntable 7, since the force of the functional element 9 will alternate during the vibration of the oscillator 2, it will reciprocally elongate and shorten, and slide relative to the turntable 7, resulting in uncontrollable damping.

[0030] The rubber plate 10 has good durability and energy dissipation capacity. The specific materials, dimensions, specifications, etc. are not limited, and the vertical distance of the oscillator 2 in the relative static balance state is determined as needed.

[0031] The above description is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Any equivalent changes, modifications, or evolutions made by those skilled in the art using the technical solutions of the present invention to the above examples still fall within the scope of the technical solutions of the present invention.

Claims

1. A low frequency tuned mass damping device, characterized in that: The low-frequency tuned mass damping device comprises a spring (1), a vibrator (2), a bearing seat (4), a bearing (5), a rotating shaft (6), a rotating disk (7), a high-strength thin rope (8) and a functional element (9); The upper end of the spring (1) is suspended on the top plate of the bridge main beam or the built-in bracket of the main beam, and the lower end is suspended on the vibrator (2); the spring (1) and the vibrator (2) constitute a traditional tuned mass damping device; the bearing seat (4) is installed on the top plate of the bridge main beam or the built-in bracket of the main beam, the bearing (5) is installed in the bearing seat (4), the rotating shaft (6) passes through the bearing (5), and the rotating disk (7) is fixedly sleeved on the rotating shaft (6); a high-strength thin rope (8) is wound around the rotating disk (7) for 1 / 4 or more of a circle, the lower end of which suspends the vibrator (2), and the other end is connected to a horizontally or obliquely arranged tension functional element (9) symmetrically arranged on the left and right; the functional element (9) is fixed inside the bridge main beam or on the built-in bracket of the main beam, and the tensioned functional element (9) provides vertical tension for the vibrator (2), thereby reducing the tension of the spring (1) when the vibrator (2) is in a static equilibrium state.

2. The low frequency tuned mass damping device according to claim 1, characterized in that: There are at least two bearing seats (4) and at least two bearings (5).

3. The low frequency tuned mass damping device according to claim 1, characterized in that: The low-frequency tuned mass damping device also includes a high-damping rubber plate (10). In order to prevent the excessive amplitude of the vibrator (2) from causing adverse effects on the spring (1) and the functional element (9), the high-damping rubber plate (10) is arranged on the bottom plate of the bridge main beam to limit the amplitude of the vibrator (2).

4. The low frequency tuned mass damping device according to claim 1, characterized in that: The inner diameter of the bearing (5) matches the diameter of the rotating shaft (6).

5. The low frequency tuned mass damping device according to claim 1, characterized in that: The low-frequency tuned mass damping device also includes a damper (3), one end of the damper (3) is connected to the vibrator (2), and the other end is connected to the bridge main beam or the main beam built-in bracket; the spring (1), the vibrator (2) and the damper (3) form a traditional tuned mass damping device.

6. The low frequency tuned mass damping device according to claim 1, characterized in that: The high-strength thin rope (8) in the connection section between the vibrator (2) and the rotating disk (7) is replaced by a functional element (9).

7. The low frequency tuned mass damping device according to claim 1, characterized in that: During the up and down vibration of the vibrator (2), the high-strength thin rope (8) is wound around or loosened around the rotating disk (7) in a clockwise or counterclockwise direction.

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