JPS62170658A - Vibration controller of building body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is used in architecture to control vibrations transmitted through the frame of a building (hereinafter abbreviated as "framework"), and to prevent adverse effects on the living environment inside the building. The present invention relates to a device for reducing.

(Prior art) In many ways, the vibrations transmitted through the building structure do not extend to the building's interior living environment.
When a slab (hereinafter abbreviated as "slab") is shaken, the vibrations may cause discomfort to the occupants of the slab, and may have an adverse effect on precision machinery, etc. on the slab.

Furthermore, if the captured images are emitted as radiated sound from the shaken slab, it may cause emotional discomfort to residents above or below the slab.

Conventionally, solutions to such cases have mainly been by replacing the frame structure with a more robust one or using a vibration-proof floating structure.

In other words, in the former case, if the target is a concrete slab, the thickness of the slab is increased or reinforcement beams are placed under the slab to increase the rigidity of the slab and reduce vibration and radiated sound.
The latter is achieved by installing a vibration-proof floating floor (hereinafter abbreviated as "floating floor") above the slab to prevent vibration forces such as falling objects from being applied directly to the slab, thereby reducing sound radiated below the slab. The effect of vibration and radiated sound can be reduced by reducing the vibration of the slab itself with a thick floor, or by installing a vibration-proof suspended ceiling (underneath the slab).
A ``vibration-proof ceiling'' (hereinafter abbreviated as ``vibration-proof ceiling'') was installed to reduce sound radiated below the slab.

[Problem that the invention seeks to solve]

However, all of these methods require large costs and
Moreover, in the former case in particular, it increases the weight of the building itself, so it is often difficult to deal with it through after-the-fact measures.

Also, most of the negative effects of such slab vibrations are
It occurs at a frequency caused by the natural frequency of the slab, so
Of the above methods, especially the latter, it is a negative method for controlling the vibration amplitude at the natural frequency, and the effect of reducing slab vibration and radiated sound is small compared to the effort expended.

The present invention is aimed at solving the above-mentioned problems.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention aims to reduce the frequency of the vibration in question to the antinode (lo) of the resonant natural frequency fs of the slab.
A dynamic damper (hereinafter r
(abbreviated as D-DJ) was installed, and its vibration control effect was applied.

[For production]

If we convert these vibration systems into electric lumped constant circuits, D-D is the spring constant Kd between the masses.

It can be regarded as a parallel circuit (circuit impedance Zd) consisting of the elements of braking resistance Rd, and anti-resonant natural frequency f
It has d.

On the other hand, the slab also has an equivalent spring mass MS and an equivalent spring constant K.
Since it can be regarded as a series circuit (circuit impedance Zs) consisting of the elements s and equal-sided splitting resistance Rs, it has a resonant natural frequency fs, and fd and fs can be expressed as follows.

fd= (1/2 π) ・f
s= (1/2 tt) ・f7T[(fiz)
Also, since the vibration system with D and 'D attached to the slab can be considered as a series circuit of the above two circuits,
The circuit impedance becomes Zd+Zs.

Now, if we adjust the mass Md and spring constant Kd so that it becomes fd'-fs, since both have an antiresonance/resonance relationship, we can make it 25<<Zd+Zs near the frequency fs. .

Therefore, since the vibration amplitude when a constant excitation force is applied to this circuit is inversely proportional to the circuit impedance, it is possible to reduce the vibration of the slab by attaching D-D to the slab. can.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Fig. 1 shows an example in which the present invention is applied to the underside of a floating floor of a building with a concrete structure, where 1 is a slab, 2 is a beam or wall of the frame that is connected to the slab 1 and supports the slab 1, and 3a has an underfloor space 6a. The floating floor plate is supported by pillars 4a and anti-vibration rubber bases 5a.

In this state, when a person jumps on the floor board 3a, the impact excitation force 10 is applied to the floor board 3a, and then the support 4
a, transmitted to the slab 1 via the vibration-proof rubber base 5a and the underfloor space 6a. At this time, since the excitation force generally has a wide imaging power spectrum, the resonant natural frequency f of slab 1
s is excited, and radiated sound 11 whose main component is fs is emitted downstairs, giving an unpleasant feeling.

D-D has the effect of reducing this radiated sound 11, and is constituted by the additional load 7, spring stand 8a, and braking resistor 9 shown in the figure.

The additional load 7 provides the depth 1d, and is preferably made of a material with high rigidity, such as a concrete block or a piece of steel.

The spring stand 8a provides an appropriate spring constant Kd and supports the additional load 7, and a vibration isolating stand such as a vibration isolating rubber or a metal spring is suitable.

The braking resistance 9 is something that provides an appropriate braking resistance Rd (Coulomb friction resistance, viscous resistance, various dampers, etc.)
Generally, the spring stand 8a is included, but it may be attached separately.

It is effective to attach this D-D at the antinode of the resonant natural frequency fs of the slab 1 if possible.

By installing D-D in this way, the impact excitation force 1
The excitation force that is excited at 0 and transmitted from the floor plate 3a of the floating floor to the support column 4a and the underfloor space 6a to the slab 1 is controlled by the action described in the action section, so that the radiation emitted from the slab 1 Sound 11 is reduced.

Note that the vibration isolating rubber base 5a may not be provided in the figure.

Figure 2 shows another example in which the present invention is applied to a vibration-proof attic of a building with a concrete structure. 10
．． 11 is 1, 2°7.9, 10.11 in Figure 1
are the same as each other.

3b is a ceiling plate of a vibration-proof ceiling having an attic space 6b, and is supported by a hanging fixture 4b and a vibration-proofing hanging fixture 5b.

In this state, if a person jumps on slab 1,
The impact excitation force 10 is applied to the slab 1 as shown in the figure, and is further transmitted to the ceiling plate 3b via the hanger 4b, the vibration-proof hanger 5b, and the attic space 6b. The excitation force at this time also excites the resonant natural frequency fs of the slab 1 as in FIG. 1, and radiated sound 11 having fs as a main component is emitted from the ceiling plate 3b, giving an unpleasant feeling to the downstairs.

In this case, D-D also supports the additional load 7 as in FIG. 1, and a vibration-proof suspension using vibration-proof rubber, metal springs, etc. is suitable.

The installation location of D-D is the same as that shown in FIG. 1, but in this case it is under the slab 1.

By installing -D in this way, the vibration of the slab 1 excited by the impact excitation force 10 is controlled by the action described in the section of the action, so that from the slab 1 to the suspension 4b, the anti-vibration suspension 5b, and The radiated sound 11 transmitted to the ceiling board 3b via the attic space 6b and emitted from the ceiling board 3b is reduced.

In addition, in the figure, the vibration isolating hanger 5b may not be provided.

FIG. 3 is an example showing the slab vibration control effect due to D/D installation, which was confirmed through a model experiment.

The specimen (model slab) is a 15 x 400 x 400 dragon, a hard vinyl chloride plate with fixed support around the periphery, the excitation point, the receiving point and D-D are installed in the center of the machine, and D-D is about 200 g on the vibration isolating table. The additional load of .

〔Effect of the invention〕

The present invention controls the vibration of a slab by simply attaching a D-D consisting of an additional load and a spring with braking resistance to the antinode of the vibration of the slab, which has an adverse effect on residents above and below the slab, precision machinery, etc. It is possible to reduce vibrations and radiated sound.

In the present invention, the increase in the amount given to the slab is approximately D-D
Since only the additional load is added, it is light, and unlike conventional slab vibration control methods, it does not impose a load on the frame structure, and it directly and effectively acts on the natural frequency of the target slab, so it is easy to use.・Inexpensive and high performance.

As explained in the embodiment section, when the present invention is intended for vibration control of slabs, it can be installed under a floating floor or in a vibration-proof ceiling, so it will not be noticeable or get in the way.

The present invention is particularly applicable to countermeasures against floor impact noise in housing complexes, etc., but it can also be applied in a similar manner not only to vibration control of slabs of building blocks but also to vibration control of walls of 1A buildings.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an example in which the present invention is applied to a floating floor as a countermeasure for preventing floor impact noise of a building, Fig. 2 is a longitudinal sectional view showing an example in which the invention is applied to a vibration-proof ceiling, and Fig. 3 is a main It is a graph showing the implementation effect of the invention. 1...Slab, 2...Beam or wall,
3a...Floating floor plate, 3b...Vibration-proof ceiling plate, 4a...Strut, 4b...Hanging tool, 5a
...Vibration-proof rubber stand, 5b...Vibration-proof hanger, 6a...Underfloor space, 6b...Attic space, 7...・Additional load, 8a... Spring stand, 8b... Spring hanging device, 9... Braking resistance, 10... Impact excitation force, 11...・・・・・・
radiated sound. Figure 1 Figure 2

Claims (1)

[Claims] (1) Vibration of a building frame characterized by a dynamic damper that is a combination of an added load and a spring with damping resistance installed near the antinode of the resonant natural frequency fs of the slab for the target vibration. Control device.