JPS6140975A - Tower shaped 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 relates to tower-like structures such as chimneys, cylinders, cylindrical structures, cylinders, and prismatic cylindrical structures.

(Prior Art) Due to the nature of the materials used, steel chimneys have a vibration damping rate lower than that of reinforced concrete chimneys, and are therefore prone to vibrations, often causing problems with vibrations caused by wind.

Conventionally, the following three methods have been adopted as countermeasures against this problem.

1) Reinforce members to prevent problems due to fatigue strength, etc., even if they vibrate.

ii) Ribs, wires, etc. are wound spirally around the cylinder body to reduce the wind excitation force and prevent vibration from occurring.

Out) Install vibration damping wire.

(Problems to be Solved by the Invention) Among the conventional methods described above, in method 1), the weight of the chimney increases due to the reinforcement of the members, and the foundation also increases accordingly, resulting in a significant increase in cost.

In method 11), although the ribs and wires wrapped around the cylinder reduce the excitation force, they also increase the resistance coefficient against the wind by about twice, which increases the wind pressure during typhoons, and by reinforcing the chimney against this, the weight decreases. The concrete volume of the foundation and the number of piles will need to be increased to prevent it from floating and falling. As with the first method, this results in a significant increase in cost.

The method described above is cheaper in cost than the above methods, but it is almost impractical because it requires a large area for laying the wire and it looks unsightly. Not provided.

(Means for Solving the Problems) The present invention was proposed to solve these problems, and includes a vibrating weight built into a viscous liquid, and the vibration weight is suspended in the liquid. This invention relates to a tower-like structure characterized in that a damping device configured to absorb vibration energy by vibration is disposed at or near the top.

(Function) As described above, in the present invention, a damping device having a built-in vibrating weight in a viscous liquid is provided at or near the top of the tower-like structure, so that wind, etc. When an external force is applied, the vibration energy is absorbed by the vibration of the weight in the viscous liquid, and as a result, the vibration damping rate of the tower-like structure in which the damping addition device is installed increases. and the amplitude decreases.

As described above, according to the present invention, the damping device absorbs vibration energy without increasing wind pressure or the weight of the structure, reduces the vibration amplitude of the chimney, and does not require extra site. It is possible to achieve the intended purpose.

(Embodiment) The illustrated embodiment in which the present invention is applied to a chimney structure will be described below.

In Figures 1 to 3, (1) is the cylinder body, (2) is the steel tower that holds the cylinder body (1), and the damping addition device frame (3) is attached to the top of the steel tower (2). There is.

An arm (5) having a weight (4) at the tip is attached to the inside of the top cover of the open frame (3) via a universal joint (6), and the inside of the frame (3) is filled with oil, etc. A highly viscous liquid (filled with force). Also, a weight (4) is placed inside the frame (3).
) is pasted with a shock absorbing material (8) such as rubber at the location where it will collide if it vibrates too much.

Since the illustrated embodiment is configured as described above, when the cylinder body (1) and the steel tower (2) vibrate due to external force such as wind, the damping device frame attached to the top of the steel tower (2)
3) The high viscosity liquid in the universal joint (
6) causes vibration as a pendulum with the fulcrum as the fulcrum.

In this way, energy is absorbed by the vibration of the weight (4) in the highly viscous liquid (force), and as a result, the vibration damping rate of the chimney equipped with the damping device increases and the amplitude decreases.

Note that the ratio between the frequency of the weight (4) of the damping device and the frequency of the chimney greatly influences the vibration damping rate of the chimney. 12th
The figure shows an example of this relationship; when the ratio of the frequency of the damping device to the frequency of the chimney is around 1.0, the damping rate of the chimney increases, and as the distance from the ratio increases, the damping rate of the chimney decreases. It can be seen that the most effective setting is to adjust the length of the arm (5) so that the frequency of the damping device is close to, but slightly lower than, the frequency of the chimney.

Furthermore, by increasing the viscosity of the liquid (7), the amplitude of the weight (4) can be lowered, thereby adding damping.

The size of the device itself can be made compact.

Figure 13 shows an example of the relationship between the viscosity of the oil and the amplitude of the weight; as the damping ratio of the damping device, that is, the viscosity of the oil, increases, the amplitude of the weight decreases exponentially. If the damping ratio of the damping device is set to about 0.5 or more, the amplitude of the weight can be made lower than the amplitude of the chimney.

If the weight (4) swings too much in the event of an emergency such as a major earthquake, it may collide with the shock absorbing material (8) placed inside the damping device frame (3), causing damage to the device. Prevented.

The mass of the weight (4) of the damping addition device greatly influences the damping rate of the chimney to which the device is attached, and Figure 14 shows an example of this relationship, and as is clear from the figure, the weight Weight (
By changing the mass of 4), the attenuation rate of the chimney can be adjusted.

In order to stop the lift vibration of the chimney due to the wind, the vibration damping rate (logarithmic damping rate) of the chimney must be approximately 0.05 or more, but the mass of the weight required for this is the modal mass (vibration) of the chimney. In the case of a chimney, it may be 1% to 5% of the total mass (approximately ~%). That is, a sufficient effect can be achieved with a small weight of about 0.1% to 1% of the total weight of the chimney. Further, when a plurality of damping adding devices are arranged as in the above embodiment, the weight of each weight of each device is further divided by the number of the same devices, and therefore becomes very small.

It should be noted that the damping addition device can be mounted anywhere to have an effect as long as the amplitude is large, but the effect is greatest near the top where the amplitude σ) is the largest.

Since the damping addition device manufactured as described above can be made small, there is almost no increase in wind pressure due to the arrangement of the device.
This eliminates the need to reinforce members to withstand wind pressure during typhoons, or increase the volume of foundation concrete or the number of piles. -1: Because it is installed at the top of a chimney, there is no need for a site to stretch damping wire, and there are no problems with appearance.

Figures 4 to 7 show another embodiment of the present invention, in which a damping device frame α3) is installed under the floor of the top platform 02) of a free-standing steel tower 0]), and a damping device frame α3) is attached to the bottom of the open frame (13). An arm (15) having 'xtma11) at the tip is attached via a universal joint α6). The frame (13
) is filled with a highly viscous liquid (I7) such as oil.
The weight α4) is wrapped with a shock absorbing material α~, and a zero-splash casting is interposed between the intermediate portion of the arm 09 and the inner wall of the frame (13).

According to the embodiment, by adding the spring (19), the frequency can be adjusted not only by changing the length of arm α9 but also by changing the spring constant or by changing the mounting position of spring a9. is also carried out.

FIG. 8 and FIG. 9 show other embodiments of the present invention, and the steel tower @
A damping addition device frame (C) is attached to the high part of the cylinder body Cυ held in the frame, and an arm C24) having a weight (C) at the tip is attached in a cantilever shape to the open frame (C). Further, the frame (c) is filled with a highly viscous liquid such as oil.

In addition, a shock absorbing material (c) such as a rubber tube is attached to the part where the weight (goods) collides inside the frame @, and the spring α in the above embodiment is omitted, and the spring α
Arm c for those in their 90s! (2) The frequency of the weight a4) can be adjusted by utilizing the flexibility of the weight itself.

Figures 10 and 11 show still another embodiment of the present invention, in which a damping device frame (to) is attached to the top of the steel tower 02 that holds the cylinder body 01), and a damping device frame (to) is attached to the side wall of the open frame C33). is weight 0
a is spring 0! It is attached via I, and the weight is configured so that it can freely move on the top surface of the bottom of the frame. be satisfied. In this embodiment, the arm in the embodiment shown in FIGS. 4 to 7 is omitted, and the spring Oo is directly attached to the weight.

(Effects of the Invention) According to the present invention, a damping device that absorbs vibration energy without increasing wind pressure can be installed at or near the top of a tower-like structure where the amplitude is greatest. Also, members of tower-like structures.

It is possible to reduce the vibration amplitude of the same structure without reinforcing the foundation etc.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of a tower-like structure according to the present invention, Fig. 2 is a vertical cross-sectional view showing details of part ① in Fig. 1, and Fig. 3 is a view taken in the direction of arrow 1 in Fig. 2. -1 [Fig. 4 is a front view showing another embodiment of the tower-like structure according to the present invention, Fig. 5 is a plan view thereof, and Fig. 6 is a longitudinal section showing details of part ① in Fig. 4. side view,
7 is a view taken along arrows Vll-Vl1 in FIG. 6, FIG. 8 is a front view showing another embodiment of the tower-like structure according to the present invention, and FIG.
The figure is a chart showing the relationship shown in FIG. Sub-Agent Patent Attorney Shige Okamoto 3 persons Figure 8 Portion 10 □ Attenuation addition! ”

Claims (1)

[Claims] A vibrating weight is built into a viscous liquid, and a damping device configured to absorb vibration energy as the weight vibrates in the liquid is disposed at or near the top. A tower-like structure characterized by: