A superstructure meta-cell damper for a building structure and a method of assembling the same

Abstract

The application discloses a superstructure meta-unit damper for a building structure and an assembling method thereof, and belongs to the technical field of civil air defense engineering. The damper comprises a connecting piece, a mass block and a rubber damper, the rubber damper is arranged on the mass block in an up-down mode, and the rubber damper is provided with the connecting piece on one side. When the meta-unit is subjected to external fluctuation and vibration, the internal vibrator also generates vibration, thereby attenuating the internal vibration wave; the local resonance of the mass vibrator consumes the external input energy; and theoretical analysis proves that the vibrator designed for a fixed frequency band, that is, the superstructure meta-unit, has a good vibration attenuation and wave attenuation effect.

Description

Technical Field

[0001] This invention belongs to the field of civil defense engineering technology, specifically relating to a superstructure element unit vibration damper for building structures and its assembly method. Background Technology

[0002] Metamaterial vibration isolation is an emerging technology that has appeared in recent years. With the in-depth development of modern building engineering, more researchers have begun to conduct in-depth research and exploration of structural vibration isolation technology, and have achieved certain research breakthroughs in the application of building structural vibration isolation technology. From a practical application perspective, metamaterial structure vibration isolation technology improves the overall flexibility and reasonably increases the damping to achieve seismic performance of building components or structures.

[0003] Traditionally, foundation vibration isolation systems mainly consist of three parts: the superstructure, the isolation device, and the substructure. By placing the isolation device between the foundation and the superstructure, the structure can flexibly slide on the foundation surface, thereby lengthening the natural period of the structural system and ultimately isolating ground vibrations, effectively reducing the structure's acceleration response. Ordinary rubber bearings have excellent performance but are very expensive. While sliding friction bearings are inexpensive, their economic efficiency is poor in low-intensity areas, and they are not suitable for some special buildings. The application of metamaterials can solve these problems. Depending on the needs, vibration dampers of different forms and frequencies can be designed, with low cost and compliance with various building or structural standards, thus achieving vibration isolation and reduction effects. Summary of the Invention

[0004] This invention provides a superstructural element vibration isolator for building structures and its assembly method. The vibration isolator is designed to specifically address complex vibration disturbances through assembled vibration damping structural units, thereby suppressing low-frequency and wide-band elastic waves and achieving high-efficiency vibration isolation performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A superstructural element vibration damper for building structures includes: a connector, a mass block, and rubber vibration dampers; the mass block has rubber vibration dampers arranged above and below it, and the connector is arranged on the outside of the rubber vibration dampers;

[0007] In the structure described above, the mass block is made of carbon steel and has 16 threaded holes with a diameter of 1 cm and a depth of 1 cm on both its upper and lower surfaces, which facilitates connection with the rubber shock absorber.

[0008] The connector has 16 circular holes with a diameter of 1 cm, which facilitates frequency control by reducing the number of rubber dampers.

[0009] An assembly method for a superstructure element vibration damper used in building structures includes the following steps:

[0010] Step 1: Determine the parameters of each component of the vibration isolator through theoretical calculations, complete the design of the vibration isolator, and select the appropriate components based on the calculation results;

[0011] Step 2: Install rubber vibration dampers on the top and bottom of the mass block according to the calculation results to form a vibration damping unit with a 4×4 arrangement on both the top and bottom.

[0012] Step 3: Arrange the vibration damping units vertically to form four types of vibration damping columns: unit cell columns, two-layer columns, three-layer columns, and four-layer columns.

[0013] Step 4: Install connectors on both the top and bottom of the column and tighten them with bolts to form a superstructure vibration-damping beam.

[0014] Beneficial effects: This invention provides a superstructural element vibration damper for building structures and its assembly method. Compared with the prior art, this invention has the following advantages:

[0015] 1. When the element is subjected to external wave vibration, the internal oscillator will also vibrate, thereby attenuating the internal vibration wave. The local resonance of the mass oscillator consumes the energy input from the outside. Theoretical analysis has proven that adding an oscillator designed for a fixed frequency band to an ordinary element, namely the superstructure element, has a good vibration reduction and wave elimination effect.

[0016] 2. The vibration damper provided by this invention exhibits excellent acceleration attenuation, with acceleration maintained within 0.5g and a maximum attenuation amplitude reaching -57.39dB. A numerical simulation model of the super-damping beam was established using LS-DYNA, and the simulation results show good agreement with the experimental results. The motion equations of the super-damping beam were established using a spring-mass system and Euler-Bernoulli beam theory. Based on Bloch's theorem, a displacement function was assumed, and the theoretical bandgap range of the super-damping beam was calculated. The results show that the experimental data and the theoretical bandgap are basically consistent. Combining the bandgap of the oscillator and the theoretical bandgap, it is believed that the vibration isolation and damping effect of the super-structure vibration damping beam is due to local resonance.

[0017] 3. In this invention, the acceleration attenuation effect of the four column types of the vibration-damping column increases progressively from a single cell to four layers. The minimum acceleration reaches 2g, and the maximum amplitude peak value decreases from 21dB to 9dB. It can be seen that the frequency domain attenuation effect of the super-damping column increases with the increase of column layers, and the peak vibration frequency also decreases accordingly. Theoretical calculations were performed on the super-damping column, a multi-degree-of-freedom dynamic equilibrium equation was established, and the theoretical bandgap regions of the four types of columns were given. It can be seen that the bandwidth increases with the increase of column layers, but the amplitude decreases with the increase of column layers. The results show that the theoretical and experimental results are basically consistent. At the same time, a comparison with the frequency of the oscillator was made, and it was found that the super-structure vibration-damping column is less affected by the local resonant oscillator, and the main attenuation effect comes from the attenuation of the layered structure. Attached Figure Description

[0018] Figure 1 This is a front view of the superstructural element vibration damper in an embodiment of the present invention;

[0019] Figure 2 This is a top view of the superstructural element vibration damper in an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the mass block in the superstructural element vibration damper in an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the connectors in the superstructure element module in an embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the vibration damping beam in the superstructure element module of this invention.

[0023] Figure 6 This is a schematic diagram of four layers of super-damping columns in the super-structural element module of this invention.

[0024] Figure 7 These are schematic diagrams of two types of rubber vibration dampers in embodiments of the present invention;

[0025] Figure 8 Experimental diagram of the frequency response of the superstructure vibration reduction beam in this embodiment of the invention;

[0026] Figure 9 Theoretical bandgap diagram of the superstructure vibration reduction beam in this embodiment of the invention;

[0027] In the diagram: 1-connector, 2-mass block, 3-rubber vibration damper. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0029] Example 1

[0030] like Figure 1As shown, a novel superstructure unit vibration damper for building structures includes: a connector 1, a mass block 2, and a rubber vibration damper 3; the mass block 2 is provided with rubber vibration dampers 2 above and below, and the connector 3 is provided on the outside of the rubber vibration dampers 2.

[0031] Mass block 2 is made of carbon steel, and has 16 threaded holes with a diameter of 1 cm and a depth of 1 cm on both its top and bottom surfaces;

[0032] Connector 1 has 16 circular holes with a diameter of 1cm;

[0033] There are two types of rubber vibration dampers 3: one type has M4 screws at both ends, and the other type has M4 threads and M4 screw holes at both ends respectively.

[0034] The aforementioned superstructure element vibration damper is assembled according to the following steps:

[0035] Step 1: Determine the parameters of each component of the vibration isolator through theoretical calculations, including the size and mass of the connectors, the size and mass of the mass block, the size, mass and Shore hardness of the rubber damper, and complete the design of the vibration isolator. Select the appropriate components based on the calculation results.

[0036] When one end of the superstructure vibration-damping beam is excited by a simple harmonic load, the equilibrium equation of the superstructure vibration-damping beam under steady-state vibration is expressed as:

[0037]

[0038] Where, u1 is the displacement of the upper connecting member of the super-damping beam, u2 is the displacement of the lower connecting member, and u r Let u represent the displacement of the internal oscillator, the point on u represents the derivative with respect to time, EI represents the bending stiffness of the equivalent super-damping beam, ρ represents the density of the super-structure damping beam, and A represents the cross-sectional area of ​​the super-structure damping beam. This represents the spring stiffness after being uniformized along the beam length. This represents the mass of the mass block after homogenization along the beam length direction, and x represents the partial derivative of u with respect to displacement;

[0039] The above formula (1) can be simplified to the following equation:

[0040] |K-ω 2 M|=0 (2)

[0041] In the above formula, K is the stiffness matrix, M is the mass matrix, and ω represents the frequency of the harmonic load on the super-damping beam;

[0042] With a harmonic force applied to the lower connector and the excitation ends being free and unconstrained, and combining the simplified model and variable parameters in the simplified equation above, the dynamic equilibrium equation for the four-story column superstructure vibration-damping column under finite period is given as follows:

[0043]

[0044] Similarly, the three-layer dynamic equilibrium equations of the super-damping column are given in Equation (4), the two-layer dynamic equilibrium equations are given in Equation (5), and the dynamic equilibrium equation of the unit cell is given in Equation (6):

[0045]

[0046]

[0047]

[0048] Based on the above formula, it can be simplified to the following equation:

[0049]

[0050] Where u represents the displacement vector of the mass, and F(t) represents the vector of the applied force.

[0051] Step 2: Install rubber vibration dampers on the top and bottom of the mass block according to the above calculation results to form a vibration damping unit with a 4×4 arrangement on both the top and bottom.

[0052] Step 3: Arrange the 5 vibration damping units in parallel and install the connectors on the top and bottom. The connectors have different lengths depending on the size of the combination. Here are the long connectors corresponding to the 5 vibration damping units. Tighten them with bolts to form a super-structure vibration damping beam; or arrange the vibration damping units in different vertical arrangements to form four types of vibration damping columns, namely single-cell columns, two-layer columns, three-layer columns and four-layer columns.

[0053] Frequency response tests were conducted on the superstructure vibration-damping beam obtained above, and the results are as follows: Figure 8 As shown, Figure 9 As shown, the theoretical band gap of the superstructure vibration reduction beam is obtained according to formula (1). The results show that the experimental data and the theoretical band gap are basically consistent. Combining the band gap of the oscillator and the theoretical band gap, it is believed that the vibration isolation and vibration reduction effect of the superstructure vibration reduction beam is due to the generation of local resonance.

[0054] The above are merely preferred embodiments of the present invention and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention, and all such changes and variations fall within the protection scope of the present invention.

Claims

1. A method for assembling a vibration damper for a superstructural element unit in a building structure, characterized in that, The vibration damper includes: a connector, a mass block, and rubber vibration dampers; rubber vibration dampers are mounted on the upper and lower parts of the mass block, and the connector is mounted on the outer side of the rubber vibration dampers. The assembly method includes the following steps: Step 1: Determine the parameters of each component of the vibration isolator to complete the design of the vibration isolator. Select the appropriate components based on the calculation results. The parameters of each component include the dimensions and mass of the connectors, the dimensions and mass of the mass block, and the dimensions, mass, and Shore hardness of the rubber vibration damper. When one end of the superstructure vibration damping beam is excited by a simple harmonic load, the equilibrium equation of the superstructure vibration damping beam under steady-state vibration is expressed as: (1)， Where, u1 is the displacement of the upper connecting member of the superstructure vibration damping beam, u2 is the displacement of the lower connecting member, and u r Let u represent the displacement of the mass block, and let the point on u represent the derivative with respect to time. Let EI represent the bending stiffness of the equivalent superstructure vibration-damping beam. Let A represent the density of the superstructure vibration damping beam, and let A represent the cross-sectional area of ​​the superstructure vibration damping beam. This represents the spring stiffness after being uniformized along the beam length. This represents the mass of the mass block after homogenization along the beam length direction, and x represents the displacement; Formula (1) simplifies to the following equation: (2) In the above formula, K is the stiffness matrix and M is the mass matrix. The frequency of the harmonic load on the superstructure vibration-damping beam; Step 2: Assemble the components selected according to the above calculations to form the vibration damping unit; Step 3: Assemble the vibration damping units into vibration damping columns or vibration damping beams according to different requirements.

2. The assembly method of the superstructural element vibration damper for building structures according to claim 1, characterized in that, The dynamic equilibrium equations for a four-story vibration-damping column superstructure under finite-period conditions are as follows: (3)。 3. The assembly method of the superstructural element vibration damper for building structures according to claim 1, characterized in that, The dynamic equilibrium equations for the three-layer damping column superstructure damping column under finite period conditions are as follows: (4)。 4. The assembly method of the superstructural element vibration damper for building structures according to claim 1, characterized in that, The dynamic equilibrium equations for the superstructure damping column with two layers of damping columns under finite period conditions are as follows: (5)。 5. The assembly method of the superstructural element vibration damper for building structures according to claim 1, characterized in that, The dynamic equilibrium equations for the unit cell damping column under finite period conditions for the superstructure damping column are as follows: (6)。 6. A superstructural element vibration damper for building structures, characterized in that, It is prepared by the method described in any one of claims 1-5.

7. The superstructural element vibration damper for building structures according to claim 6, characterized in that, The mass block is made of carbon steel.

Images