JP2022180734A - Pendulum type vibration control device - Google Patents

Abstract

To provide a vibration control device capable of reducing a size of occupied space as much as possible and easily performing natural period adjustment in multiple directions to enable reduction in response in multiple directions of a building.SOLUTION: A vibration control device includes a structure, a pendulum type synchronization mass damper attached to the structure, and a rack-and-pinion having a flywheel provided between the structure and the pendulum type synchronization mass damper.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pendulum type vibration damping device, and more particularly to a pendulum type vibration damping device having a rotary inertia mechanism.

Conventionally, a vibration damping device capable of minimizing an occupied space as much as possible, facilitating multi-directional natural period adjustment, and reducing the multi-directional response of a building, and a building vibration damping device equipped with the same. A device is provided, for example, in Japanese Patent Application Laid-Open No. 2020-101081 (Patent Document 1). Such a damping device includes a plurality of damping columns provided with laminated rubber bodies (horizontal spring elements), a connecting beam that is connected above the laminated rubber bodies of the plurality of damping columns, and a connecting beam. and an oil damper and/or rotational inertia mass damper having one end connected to the building A and the other end connected to the connecting beam. constitutes B.

On the other hand, a tuned mass damper (abbreviated as "TMD") is known as a vibration damping device. This is to control the vibration of the main body of the structure by forming a secondary vibration system (TMD) for the target structure. FIG. 7 shows the vibration model of the structure-TMD system. The mass m _T of the TMD is about several percent of the mass m _s of the structure. Since the natural frequency of the TMD is adjusted to a numerical value substantially equal to the natural frequency of the structure to be damped, when the structure starts to shake due to some disturbance, the TMD also starts to shake. At that time, since the vibration energy is absorbed by the damper C _T installed in the TMD, the vibration of the structure is also suppressed. In order to efficiently exhibit the damping effect of the TMD, it is necessary to adjust the ratio of the TMD to the natural frequency of the structure and the damping constant of the TMD to optimum values. The "optimal numerical value" varies depending on the characteristics of the disturbance that causes vibration, and various theoretical formulas have been proposed (Non-Patent Document 1).

Japanese Patent Application Laid-Open No. 2020-101081 (summary, etc.) Hiroki Yamaguchi: Structural Vibration/Control, Kyoritsu Shuppan (1996)

Vibration damping devices are roughly classified into vertical vibration damping devices and horizontal vibration damping devices depending on the direction of vibration of a target structure. The present invention is directed to a horizontal vibration damping device. FIG. 7 shows a vibration model in the horizontal direction. For simplicity, the structure is supported by a spring. In the present invention, a pendulum structure (FIG. 8) is assumed as a method of realizing horizontal vibration. . Hereinafter, a damping device having this pendulum structure (single pendulum) will be referred to as a "pendulum type TMD".

The natural frequency of a pendulum TMD depends on the length of the pendulum. In other words, since the natural frequency changes in proportion to the square root of the reciprocal of the pendulum length, the pendulum length is relatively longer.

However, when the above-mentioned conventional pendulum type TMD is installed on the roof of a skyscraper, etc., it is necessary to secure a large and tall space on the roof in order to accommodate the long pendulum structure. It is necessary to construct an incidental frame to support the In addition, when applying to a building with different natural periods in two directions, the length of the pendulum can be changed rationally, or the length of the pendulum must be different in each direction. The system becomes very complicated. That is, there is a problem that the length of the pendulum restricts the installation space.

When designing a damping device in parallel with the design of a building, the length of the pendulum is assumed based on the analytical value of the natural frequency of the building. In order to synchronize with the shaking, it is necessary to adjust the length of the pendulum according to the natural frequency of the actual structure. In order to adjust the length of the pendulum, it is conceivable to directly change the length of the pendulum. Since this is a fairly large-scale operation, there is the problem that it is difficult to adjust the natural frequency.

A multi-stage pendulum damping device is available as a method of avoiding the pendulum length restriction and realizing a pendulum with a low frequency (long period). This is shown in FIG. This method simply divides one pendulum into multiple pendulum stages, and has the advantage of reducing the height of the device while ensuring the natural frequency of the normal pendulum. However, there arises a problem that the mechanism becomes complicated and the plane dimension of the device becomes large. Moreover, as a result, the manufacturing and installation costs of the device increase, resulting in a significant cost increase.

The present invention has been made to solve the above-mentioned problems. It is possible to reduce the occupied space as much as possible. To provide a vibration damping device capable of easily tuning corresponding to multi-directional natural periods of a building by adjusting a flywheel and reducing responses in each direction. .

A pendulum-type TMD according to the present invention includes a structure, a pendulum-type tuned mass damper attached to the structure, and an engaging member having a flywheel provided between the structure and the pendulum-type tuned mass damper. including.

Preferably, the engaging member is a rack and pinion.

The rack may be provided on the tuned mass damper and the pinion may be provided on the structure as an axis of rotation for the flywheel, the pinion may be provided on the tuned mass damper as an axis of rotation for the flywheel and the rack may be: It may be provided in a structure.

According to one embodiment of the invention, the engaging member is a ball screw with flywheel.

Preferably, a plurality of ball screws with flywheels are provided.

In this invention, by incorporating a rotary inertia mechanism (flywheel) into the pendulum type TMD, it is possible to lower the frequency without changing the length of the pendulum. In addition, the natural frequency can be adjusted simply by changing the inertial force of the flywheel, greatly simplifying the work of adjusting the frequency.

As a result, it is possible to minimize the space occupied, and by arranging a set of TMDs in each direction and adjusting the flywheel of each TMD, it is easy to tune for the natural period of the building in multiple directions. It is possible to provide a damping device capable of reducing the response in each direction.

FIG. 4 is a diagram showing a dynamic model of a pendulum-type TMD with a rotary inertia mechanism; FIG. 2 is a diagram showing the configuration of a pendulum-type TMD having a rotary inertia mechanism used in experiments of the present invention; 1 is a diagram showing a configuration of a pendulum-type TMD according to an embodiment of the invention; FIG. FIG. 10 is a diagram showing the configuration of a pendulum-type TMD according to another embodiment of the present invention; FIG. 10 is a diagram showing the configuration of a pendulum-type TMD according to still another embodiment of the present invention; FIG. 10 is a diagram showing the configuration of a pendulum-type TMD according to still another embodiment of the present invention; It is a figure which shows the vibration model of TMD. It is a figure which shows the image of pendulum-type TMD. It is a figure which shows the image of the conventional pendulum-type TMD.

First, the theoretical background of this invention will be explained. The inventor derived a formula for calculating the natural frequency of a pendulum-type TMD incorporating a rotary inertia mechanism (flywheel). Fig. 1 shows a dynamic model of a pendulum-type TMD with a flywheel, which is the premise.

Assuming a rack and pinion type transmission mechanism, the force acting on the flywheel is defined as follows.

As described above, the apparent length of the pendulum can be greatly changed according to the rotational inertia, and the natural frequency can be adjusted with simpler on-site work than the method of changing the actual length of the pendulum.

Based on the above considerations, the inventor conducted experiments on the effects of the pendulum type TMD having a flywheel. FIG. 2 shows the pendulum-type TMD with a flywheel used in the experiment.

FIG. 2 is a diagram showing a specific configuration of a pendulum-type TMD having a rotary inertia mechanism used in experiments. Here, a rack and pinion is installed, and the flywheel rotates with the horizontal movement of the pendulum, creating a mechanism that generates rotational inertia.

As shown in FIG. 2, rack and pinions 12 and 13 are installed on the lower surface of the weight 11 of the TMD. As the rack 12 moves, the flywheel 16 attached to the pinion 13 engaged with the rack 12 rotates to generate rotational inertia.

The flywheel has a detachable structure, and multiple thin semicircular discs are installed so that it can be detached manually. By the way, the replacement semi-circular flywheels used in the experiments described later had a thickness of 10 mm, and a total of eight flywheels were installed so that the rotational inertia could be adjusted. In addition, the mass of one semicircle is approximately 9 kg, which is sufficiently heavy for one person to replace.

The position of this rack 12 can be freely selected on the wall surface of the TMD mass 11 . Further, the pinion 17 may be arranged at any portion such as the lower portion, the upper portion, or the side portion of the rack 12 .

If the rack 12 has an appropriate curvature, the flywheel will drive more smoothly. The curvature corresponds to the pendulum's arcuate motion and is set downwards.

Next, another embodiment of the pendulum type TMD will be described. FIG. 3 is a diagram showing another embodiment of the pendulum TMD. Referring to FIG. 3, in this embodiment, the pendulum type TMD 20 has a TMD mass 21 provided with a flywheel 26 having a pinion as its axis, and a rack 22 provided on a support portion 29 on the floor surface 28 of the structure. It is

FIG. 4 is a diagram showing yet another embodiment. In this embodiment, a ball screw system is used to drive the flywheel. Referring to FIG. 4, it is an embodiment in which ball screws 33a and 33b are fixed to the wall surface of the mass 31 of the TMD and the floor surface 38 of the structure with hinges at both ends to drive flywheels 36a and 36b. The fixing positions of the ball screws 36a and 36b can be freely selected on the wall surface of the mass 31 of the TMD.

FIG. 5 shows an embodiment in which the flywheel is driven using a ball screw system. In this embodiment, a flywheel 46 is driven by fixing a ball screw 43 between the lower surface of the mass 41 of the TMD and the floor surface 48 of the structure with hinges 45a and 49 at both ends. The fixing position of the ball screw 43 can be freely selected on the lower surface of the mass 41 of the TMD.

FIG. 6 shows an embodiment in which a ball screw system is used to drive the flywheel. In this embodiment, a flywheel 56 is driven by fixing a ball screw 53 to the upper surface of the mass 51 of the TMD and the ceiling surface 58 of the structure with hinges 55 and 58a at both ends. The fixed position of the ball screw 53 can be freely selected on the upper surface of the mass 51 of the TMD.

Next, experimental results will be described. In order to confirm the effect of the rotary inertia mechanism, the thickness of the flywheel 16 was changed and the natural frequency of the device under each condition was measured. Table 1 shows the experimental cases. Experiments were conducted without a flywheel (No. 1) and with different flywheel thicknesses to impart rotational inertia (Nos. 2 to 4).

In order to confirm the effect of the rotary inertia mechanism, the thickness of the flywheel was changed and the natural frequency of the device was measured under each condition. Table 2 shows the experimental results.

The apparent length of the pendulum is shown in the table. Without the rotary inertia mechanism, the pendulum length was 2.76m, but with a 90mm flywheel, the apparent pendulum length ( It can be seen that the length required for a normal pendulum without a flywheel is 4.23m (approximately 1.5 times longer).

Table 3 shows a comparison with the theoretical calculation. Although the natural frequency of the experimental device is slightly larger than that of the theoretical calculation, the results of both are almost consistent with an error of about 2%.

From the above, the following points became clear.

A longer period of the pendulum type TMD can be achieved by providing a rotary inertia mechanism (flywheel).

Apparent pendulum length can be adjusted by the rotary inertia mechanism.

A mechanism that converts pendulum motion into rotary motion (rack and pinion, ball-nut system) is effective.

It is possible to adjust the length of the pendulum by exchanging the member that imparts rotational inertia.

Simply, it is possible to change the thickness and size of the disk and change the inertia force adjusting member.

Although embodiments of the invention have been described with reference to the drawings, the invention is not limited to the illustrated embodiments. Various modifications can be made to the illustrated embodiment within the same scope as the present invention or within an equivalent scope.

According to this invention, by incorporating a rotary inertia mechanism (flywheel) into a pendulum-type TMD, it is possible to easily lower the natural frequency without changing the length of the pendulum. be done.

10 pendulum type TMD, 11 TMD weight, 12 rack, 13 pinion, 14 pendulum, 16 flywheel, 18 floor of structure.

Claims (6)

a structure;
a pendulum tuned mass damper attached to the structure;
and an engaging member having a flywheel between the structure and the pendulum tuned mass damper. 2. The pendulum type vibration damping device according to claim 1, wherein said engaging member is a rack and pinion. said rack being mounted on said tuned mass damper,
3. The pendulum type vibration damping device according to claim 2, wherein said pinion is provided on said structure as a rotating shaft of said flywheel. The pinion is provided on the tuned mass damper as a rotation axis of the flywheel,
3. The pendulum type vibration damping device according to claim 2, wherein the rack is provided on the structure. 2. The pendulum type vibration damping device according to claim 1, wherein said engaging member is a ball screw having a flywheel. 6. The pendulum type vibration damping device according to claim 5, wherein a plurality of ball screws having said flywheel are provided.

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