A low frequency tuned mass damper device that reversely stretches a compression spring

Abstract

The present application belongs to the technical field of low-frequency vibration control, and aims at the problem that the traditional tuned mass damper is limited in vertical space use due to the excessive spring net deformation under low-frequency conditions, and provides a low-frequency tuned mass damper device which reversely stretches the compression spring. The device fully realizes the compression large deformation and reverse stretching deformation of the spring in the limited vertical space through the way of over-compression and reverse stretching of the compression spring, so as to achieve the required low stiffness of the vibration system. The low-frequency tuning can be realized in the limited vertical space of the bridge girder, and the frequency application range of the tuned mass device is greatly expanded. At the same time, the stability problem of the traditional compression spring mass body placed on the spring and the problem of excessive and unstable damping caused by the increase of the guide component are avoided. The device has simple structure, low damping, low space requirement and good stability, and can be applied to vertical, lateral and torsional multi-type low-frequency vibration control of various engineering structures.

Description

Technical Field

[0001] This invention belongs to the field of low-frequency vibration control technology and relates to a low-frequency tuned mass damping device that reverses the stretching of a compression spring. Background Technology

[0002] Long-span bridges with main spans of over 1,000 meters may experience vertical or torsional vortex-induced vibrations (vortex-induced vibrations) with frequencies below 0.2 Hz under wind loads, affecting driving comfort and even safety. For example, the vortex-induced vibration frequencies of the Xihoumen Bridge and Humen Bridge in Zhejiang Province are as low as 0.1 Hz and 0.17 Hz, respectively. Traditional tuned mass dampers, if installed within a 3m vertical space within the main beam, can be used to control high-frequency (e.g., >0.3 Hz) vortex-induced vibrations in bridges. Tuned mass damper springs generally take the form of tension or compression, and their deformation under the action of the mass body... With vibration frequency Generally satisfied The relationship between tension springs and compression springs is complex. Tension springs offer flexible installation and structural stability, but for main beams with only 3-4m of vertical installation space, after deducting the original spring length, mass thickness, and vibration space, the space left for spring tensile deformation is at most 2-3m, making them suitable for frequencies generally no lower than 0.3Hz. Compression springs are compact and have a larger deformable range than tension springs. For main beams with 3-4m of vertical installation space, spring compression deformation can reach 6m or even 8m, theoretically suitable for vortex-induced vibration control at 0.15Hz. However, installation is difficult, and they face compressive stability issues, requiring additional lateral stabilization measures. This leads to complex construction and inevitably introduces frictional damping caused by the guiding device, which is difficult to control precisely, severely impacting vibration control effectiveness. To achieve lower vibration frequency tuning, inertial capacitance elements can be introduced to reduce the static deformation of the spring, but their control efficiency decreases significantly, and their control effect is more sensitive to various parameters such as frequency ratio and damping ratio. Their economic efficiency and applicability are also somewhat lacking, making them difficult to apply in practical engineering. Summary of the Invention

[0003] Addressing the technical limitations of traditional tuned mass dampers and tuned mass inertial-capacitive dampers in low-frequency vibration control, this invention aims to provide a novel concept: a tuned mass system with frequencies as low as 0.1Hz achieved by supporting a mass body with springs within a 3-4m vertical space of the main beam of a long-span bridge. Taking a compression spring with an initial length of approximately 25m as an example, the bottom coil of the spring is fixed, and compression is gradually applied from the top coil. Each coil of the spring is stretched in the opposite direction from the central hole or the outer periphery. Ultimately, all the original coils of the spring can be lower than the bottom coil. At this point, the compression spring becomes a reverse-tension spring, with an actual deformation exceeding 25m. Suspending a suitable mass ensures that the spring is essentially under tension, achieving a frequency as low as 0.1Hz.

[0004] Technical solutions of the present application:

[0005] A low-frequency tuned mass damper device for reverse stretching of compression spring, comprising a spiral compression spring, a mass body and a damping element;

[0006] The spiral compression spring is placed vertically, horizontally or obliquely, the bottom ring is fixed on a corresponding size ring, and pressure is continuously applied to the spiral compression spring at the top ring or the middle local position, until the spiral compression spring top ring penetrates or passes through the bottom ring and turns over, and the spiral compression spring is fixed in the turned over state; the bottom ring of the spiral compression spring in the turned over state is installed on the top plate of the box girder or the top of the built-in support of the box girder, at this time the spiral compression spring is a reverse spiral compression spring; the top ring of the spiral compression spring is at the lowermost active end and is connected with the mass body for hanging the mass body; the reverse spiral compression spring is used to balance the gravity of the mass body and provide stiffness for the vibration system, and the two form a tuned mass device; the original length of the spiral compression spring is large and the stiffness is small, although the space occupied after reverse stretching is small, it can bear a large gravity of the mass body and maintain a relatively low stiffness basically unchanged, so low-frequency tuning can be realized. Since the spiral compression spring is in a compressed state initially and in a tensioned state in the working state, it does not involve the instability problem of compression spring and does not need to increase the transverse connection, so the damping is very low. In addition, the damping element with appropriate parameters is set according to the needs, which provides additional damping for the low-frequency tuned mass damper device to achieve optimal control effect.

[0007] The spiral compression spring material, size, cross-sectional form is not limited, in order to facilitate super compression deformation, and reverse stretching, the spring index should be as large as possible (such as > 20). The spring is made into a tapered (tower-shaped) spring with gradually changing outer diameter, and the taper is not limited and is designed according to the needs. The taper is zero, which means a traditional equal coil diameter spring. The larger the taper, the easier it is to super compress and reverse stretch, but the taper should not be too large, otherwise the strength and stiffness of adjacent coil layers of the spring will be greatly different, and the stress will be unreasonable. The spiral compression spring may not be convenient for super compression and reverse stretching due to its excessive length, so it can be processed by segmental turning and finally connected in series. It can also be symmetrically arranged on both sides of the torsional vibration structure to control low-frequency torsional vibration. When the spiral compression spring is used as a horizontal spring for low-frequency vibration control, and the horizontal space is limited, the spiral compression spring can also be super compressed and reverse stretched in the same way as above to realize low-frequency tuning. The spiral compression spring is arranged vertically, horizontally or obliquely.

[0008] The mass body is not limited in specific material and structure, and the space limitation is more relaxed than that of the mass body (usually a steel plate with high density) used in the traditional tuned mass damper, so a concrete block or a water tank with smaller density and lower cost by one or even two orders of magnitude can be used, which has strong engineering application competitiveness.

[0009] The damping element is used for adjusting the damping of the low-frequency tuned mass damping device, so that the system damping reaches the ideal target value, and the vibration control effect is ensured, and the form is not limited.

[0010] The beneficial effects of the application are: (1) the initial compression spring stress state is changed from compression to tension, the axial stiffness is basically unchanged, the deformation amount can be larger in the same vertical space, so a lower frequency can be realized compared with the traditional compression spring; (2) the working state of the traditional compression spring is always under compression, and the stability problem exists, while the working state of the spring of the application is always under tension, and the stability problem does not exist; (3) the application does not need to add multiple transverse stabilizing plates or increase vertical guide rods, and has simple structure, low damping and good stability, which ensures the vibration control efficiency; (4) a lower tuning frequency can be realized in a limited vertical space, which greatly expands the frequency application range of the tuned mass device; (5) the spring of the application can be arranged vertically, horizontally or obliquely, and can be set according to needs, and is free in form, and can be applied to vertical, lateral and torsional multi-type low-frequency vibration control of various engineering structures, and has wide application scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a structure diagram of a low-frequency tuned mass damping device for super-compression-reverse stretching of a compression spring installed in a bridge girder;

[0012] Figure 2 It is a super-compression-reverse stretching deformation process schematic diagram of a positive conical spring;

[0013] Figure 3 It is a super-compression-reverse stretching deformation process schematic diagram of an inverted conical spring;

[0014] In the figure: 1 spiral compression spring; 2 mass body; 3 damping element; 、 、 Three marks of the uppermost coil, the intermediate coil and the lowermost coil of the conical spring are respectively used to intuitively show the super-compression-reverse stretching deformation process of the spiral compression spring. DETAILED DESCRIPTION

[0015] The specific implementation mode of the application will be described in detail in combination with the technical scheme and the drawings.

[0016] As shown in Figure 1 , a low-frequency tuned mass damping device for reverse stretching of a compression spring includes a spiral compression spring 1, a mass body 2 and a damping element 3. The specific implementation mode will be described below by taking two typical spring vertical placement conditions as examples. The specific steps are: the spiral compression spring 1 is vertically placed, and the bottom coil is fixed on a circular ring with appropriate size. For Figure 2In the shown case, axial pressure is applied to the top ring to compress it sufficiently until the spring is turned over from the middle through the bottom ring except the lowermost ring. For Figure 3 In the shown case, axial pressure is applied to the top ring to compress it sufficiently until the spring is turned over from the middle through the bottom ring except the lowermost ring. For

[0017] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application in any form. Any equivalent changes, modifications or evolution of the above examples by those skilled in the art using the technical solutions of the present application shall still fall within the scope of the present application.

Claims

1. A low frequency tuned mass damper device for reverse-stretching a compression spring, characterized by, The low-frequency tuned mass damper device comprises a helical compression spring (1) and a mass body (2). The helical compression spring (1) is vertically, horizontally or obliquely placed, the bottom ring is fixed on a corresponding size circular ring, pressure is continuously applied to the helical compression spring (1) at the top ring or the middle local position of the helical compression spring (1) until the helical compression spring (1) is turned over when the top ring of the helical compression spring (1) penetrates or is sleeved through the bottom ring, and the helical compression spring (1) is fixed in the turned-over state; the bottom ring of the helical compression spring (1) in the turned-over state is installed on the top plate of the box girder or the top of the built-in support of the box girder, and the helical compression spring (1) is a reverse helical compression spring (1) at this time; the top ring of the helical compression spring (1) is at the lowermost movable end and is connected with the mass body (2) and used for suspending the mass body (2); the reverse helical compression spring (1) is used for balancing the gravity of the mass body (2) and providing stiffness, and the two form the low-frequency tuned mass damper device.

2. The low-frequency tuned mass damper device of claim 1, wherein, The low-frequency tuned mass damper device further comprises a damping element (3) for providing required damping for the low-frequency tuned mass damper device.

3. The low-frequency tuned mass damper of claim 1, wherein, The helical compression spring (1) is made into a tapered or tower-shaped spring.

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