JPS63181869A - Vibration suppressing apparatus of structure - 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 "Industrial Application Field" The present invention is designed to reduce the vibration of structures installed in architectural and civil engineering structures, in order to suppress vibrations excited in architectural and civil engineering structures by earthquakes, wind, etc. This invention relates to a suppression device.

"Conventional technology and its problems" In recent years, architectural and civil engineering structures have become larger and more diverse due to factors such as the development of high-strength materials, progress in construction technology, and development of structural analysis technology using computers. In addition to being lightweight, it has a structure that is highly flexible against external forces. Lightweight and flexible structures like this tend to have low natural frequencies and low internal vibration damping, so they are susceptible to various unpredictable vibrations due to external forces such as earthquakes and wind. This may occur.

In particular, as mentioned in Moe's article, as structures become larger, the amplitude of vibrations excited by external forces increases. There was even a risk that stress beyond the permissible range would be applied to the structure of the object.

Therefore, in the specification of Japanese Patent Application No. 60-241045, the inventor of the present application proposes to vibrate at a predetermined position of a structure with the same period as the natural vibration period of this structure and with a required phase difference. A vibration suppressing device has been proposed in which a storage tank for storing a liquid is provided and the vibration of the structural object can be suppressed by the vibration of the liquid, thereby solving the above-mentioned problem.

One embodiment of the vibration suppressing device shown in the above-mentioned specification had a structure in which a cylindrical storage tank was provided on the roof of a structure, and liquid was stored in this storage tank. by the way,
The effective mass of the liquid stored in this storage tank is preferably 1150 to 1/100 of the mass of the structure in view of the damping effect of the vibration suppressor and the structural design of the structure. Installing a large-scale vibration suppression device on a structure is a large-scale work, and the installation location is limited to places where a large space can be secured, such as the rooftop.
Some kind of countermeasure was needed.

In view of the above-mentioned problems, the present invention has been developed by developing the vibration suppressing device previously proposed by the inventor of the present invention, and is easy to install, move, and remove, and can be installed anywhere. The purpose is to provide a vibration suppression device.

"Means for Solving the Problem" In order to solve the problem, the present invention provides vibration suppression for a structure that is installed at a predetermined position of a structure and suppresses vibrations excited in the structure. The device is comprised of a plurality of box-shaped tanks that can be connected vertically and horizontally; It consists of natural vibration and a liquid that vibrates with a required phase difference.

"Embodiments" Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a vibration suppressing device for a structure, which is an embodiment of the present invention. In the figure, reference numeral 1 denotes a vibration suppression device, and this vibration suppression device 1 is installed at an arbitrary location in the building or civil engineering structure S (in the illustrated example, on the floor slab 2 of the structure S).

This vibration suppressing device 1 includes a plurality of tanks 4.4 each having a substantially box-like external shape and arranged in rows in the horizontal and vertical directions of the structure S.
・and the liquid 5.5, which is stored in the tanks 4.4, . . . under conditions such that the vibration period is the same as the natural vibration period of the structure S. . More specifically, the liquid 5 is stored in the tank 4 in the vertical direction (X in the figure).
direction) is made the same as the natural vibration period of the structure S in the X direction, and the tank 4 is lateral (Y direction in the figure).
are stored in the tank 4 so that the vibration period of the structure S is the same as the natural vibration period of the structure S in the Y direction. The vibration suppressing device l has its tank 4.4,...
The total mass of all the liquids 5.5, .

Further, the tank 4 is provided with a graduated viewing window 6 made of a transparent material such as glass on its side, and a liquid supply window 6 whose tip extends to the bottom of the tank 4. A port 7 for use is provided. This pose 7 is
Its base end is joined to one hose and connected to a liquid supply section (not shown). As a result, the amount of liquid 5 stored in the tank 4 can be finely adjusted after the vibration suppression device l is installed, and the amount of liquid 5 stored in the tank 4 can be finely adjusted.
・Liquid in 5.5,...The storage amount is assumed to be the same amount. Further, the inner surface of the side wall of the tank 4 is formed into an uneven surface, thereby making it possible to adjust the vibration damping rate of the liquid 5 due to an increase in the frictional force between the liquid 5 and the inner surface of the tank 4.

It is preferable that the tank 4 is made of a material that does not rot even after long-term use (for example, made by Plus Deck), and similarly, the liquid 5 is made of a viscous liquid that does not evaporate easily even after long-term use (for example, Ura). It is preferable that However, the materials of these tanks 4 and liquid 5 are
The material may be determined as appropriate depending on the construction conditions, etc., and is not limited to the above-mentioned materials. Further, the vibration suppressing device l is
For example, it is preferable to install it on a support base made of a laminated structure of an elastic body such as rubber and a steel plate.

Next, the operation of the vibration suppressing device 1 having the above configuration will be explained.

The vibration system including the structure S and the vibration suppression device I includes a second
Can you approximate and simplify the vibration model as shown in the figure? This vibration model has a spring constant K. quality ff1 through a spring 8A and a dashpot 10A with a damping rate hQ.
M. An object 9 of quality MMl is transmitted through a vibration system A (vibration model of structure S) in which an object 9A of
This is a model in which a vibration system B (vibration model of the liquid 5 in the vibration suppressing device 1) in which the vibration system B is supported is connected in series.

Here, as mentioned above, the vibration suppressing device 1 is composed of a plurality of tanks 4.4, . . . and liquids 5.5, . . . stored in these tanks 4.4, . However, since the vibration period of the liquid 5 stored in each tank 4 matches the natural vibration period of the structure S, these liquids 5, 5, . . . vibrate as one. Therefore, as described above, the vibration suppressing device 1 can be approximated by one vibration system B without any problem.

In such a vibration model, when vibration system A starts to vibrate due to an external force such as an earthquake or wind applied to object 9A, vibration system B! Since the vibration starts with a phase delay of /4 period, the vibration of the vibration system A can be suppressed by matching the vibration periods of the vibration systems A to H.

Here, since the mass of the object 9B is about 2% of that of the object 9A, the natural vibration period T of the structure S is. is the quality fiM determined from the standpoint of trench construction design. and spring constant K. It is determined almost uniquely by Therefore, the dimensions and capacity of the tanks 4 are adjusted so that the vibration period of the vibration suppressing device l, that is, the vibration period T + of the liquid 5 stored in each tank 4 matches the natural vibration period T0 of the structure S. and the storage amount of the liquid 5 may be set. The behavior of the liquid 5 stored in the tank 4 can be analyzed as follows.

The relationship between the fifth-order natural vibration period Tj of sloshing and the fifth-order natural circular frequency ωj is expressed by the following equation.

Tj=2π/ωj (1) In the above equation (1), ■] is the liquid storage depth,
When 9 is the gravitational acceleration, the above ωj is a quantity given by the following equation.

ωj==, fina7 purchase h(kj) ") ・・・・・・
-(2) Further, kj in the above equation (2) is given by the following equation, assuming that the width of the tank 4 is 28.

kj=(2j −1)π/2a -----C3)
Therefore, the natural vibration period Tj of sloshing can be obtained from equations (1) to (3) shown above, and in particular, the natural vibration period of first-order sloshing can be used to suppress the vibration described above. .

As explained above, according to the vibration suppressing device 1 of this embodiment, vibrations excited in the structure S by external forces such as earthquakes and wind can be suppressed. Here, this vibration suppression device (2) consists of a plurality of unitized tanks 4.4,...
and the liquid 5 stored in these tanks 4.4, .
．． 5. Since it consists of..., the installation of device 1,
Each work such as moving and removal is performed on each of the tanks 4.4,...
Therefore, each work such as installation, movement, and removal of the device I becomes very easy. Also, each tank 4.4,...
・There is no particular limitation on the method of arranging these tanks 4.4,
The number of liquids 5.5, . . . stored in the structure S is such that the total mass is within the range of 1150 to 1/100 of the mass of the structure S. Therefore, it is possible to arrange it with great flexibility, and its installation location is not limited.

Therefore, according to this embodiment, it is possible to realize a vibration suppressing device for a structure that is easy to install, move, and remove, and can be installed anywhere.

The vibration damping effect of the vibration suppressing device 1 of the present invention will be demonstrated by showing the results of a simulation experiment conducted by the present inventor below. As shown in Fig. 3, the experimental system consists of a five-layer model simulated structure S (mass M.-4QOk
gX5 layer, -order solid period T. =0.41 seconds) on the rooftop,
Vibration suppressor 1 of the present invention (total mass of liquid 5 M + =
This is an experimental system in which a 52 kgl-order natural period T, = 0.41 seconds) was installed. Figure 4 shows the displacement of the fourth layer of the simulated structure S when a random wave (EL -CENTI?O-NS wave) is added to such an experimental system without the vibration suppression device l. FIG. 5 shows the displacement of the fourth layer of the simulated structure S when the device I is present. As can be seen from the illustrated results, it can be seen that the vibration of the simulated structure S is suppressed by the vibration suppression device I.

Furthermore, as a result of the simulation, the ratio between the total effective mass M1 of the liquid and the quality qMo of the structure S is 1, M, /M
, = 1150 to 1/100 - = - (4) It has been found that an effective vibration suppressing effect can be achieved. In other words, the total effective quality ff1M.

The quality of the structure is ff1M. If it is less than 1/100, sufficient vibration damping effect cannot be obtained, and if it is more than 1150, the influence of the mass of the liquid on the structural design of the structure becomes large, and the structural design of the structure must be carried out again. Since this may be necessary, it is necessary to set the ratio as shown in equation (4) above.

It should be noted that the vibration suppressing device 1 for a structure according to the present invention is not limited to the above embodiment. - As an example, the vibration suppression device 1 is not only installed on the floor of the structure S as in the above embodiment, but also suspended from the lower surface of the floor slab 2, that is, the ceiling, as shown in FIG. It may be installed in any space within the structure S due to its good transportability. Further, the shape of the tank 4 may be changed to various shapes such as a cylindrical shape, a spherical shape, and an elliptical shape depending on the shape of the structure S and installation conditions. In this case, the above-mentioned theory may be changed as appropriate, and the dimensions of the tank, the liquid storage depth, etc. may be set based on the formula according to the shape. Furthermore, by appropriately arranging a partition plate or the like in the tank 4 to provide a wave-dissipating effect, it is also possible to adjust the vibration damping rate caused by viscous resistance. Note that when the tank 4 is made of a steel plate, the durability of the inner body of the tank 4 can be increased by mixing a rust preventive agent into the liquid 5.

"Effects of the Invention" As explained in detail above, the vibration suppression device for a structure according to the present invention includes a plurality of unitized tanks, and a vibration suppressing device for a structure that is Because it is composed of a liquid that vibrates with the same vibration period and with the required phase difference from the natural vibration of this structure,
Each work such as installation, movement, and removal of the device can be performed for each tank, and therefore, each work such as installation, movement, and removal of the device becomes very easy. Moreover, since the method of arranging each tank is not particularly limited, it is possible to arrange the tanks with great flexibility, and the installation locations are not limited. Therefore, according to the present invention, it is possible to realize a vibration suppressing device for a structure that is easy to install, move, remove, etc., and can be installed anywhere.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state in which a vibration suppressing device for a structure according to an embodiment of the present invention is installed in a structure, FIG. 2 is a schematic diagram showing a vibration model of the structure and the vibration suppressing device, Third
The figure is a schematic diagram showing an overview of the experimental system of the simulation experiment, and Figure 4 is a diagram showing the vibration situation of a simulated structure that is not equipped with a structure vibration suppression device that is an embodiment of the present invention.
FIG. 5 is a diagram showing the vibration state of a simulated structure equipped with a vibration suppressing device, and FIG. 6 is a sectional view showing another embodiment of the present invention. S...Structure, l...Vibration suppressor,
4...Tank, 5...Liquid. Outsourcer Shimizu Construction Co., Ltd.

Claims (1)

[Claims] A vibration suppression device for a structure that is installed at a predetermined position of a structure and suppresses vibrations excited in the structure by external forces such as earthquakes and wind. A plurality of box-shaped tanks that can be connected in series; 1. A vibration suppression device for a structure, comprising a liquid that vibrates.