JPH041375A - Multidegree-of-freedom dynamic damping method and multidegree-of-freedom dynamic damper - Google Patents

Abstract

PURPOSE:To damp vibrations by installing springs and dampers to a structure and inertial mass bodies and among the inertial mass bodies respectively and setting the springs and the dampers so as to have natural frequency corresponding to a plurality of natural frequencies of the structure. CONSTITUTION:A multidegree-of-freedom dynamic damper A is composed of a plurality of inertial mass bodies 1-3, a plurality of dampers 11-13 and a plurality of elastic members 21-23, etc. The damper 11 is mounted between a strut 31 and the mass body 1, the damper 12 between the mass bodies 1, 2 and the damper 13 between the mass bodies 2, 3 respectively while the dampers 11-13 and the members 21-23 are given natural frequency corresponding to a plurality of natural frequencies of a building B. When vibrations consisting of a plurality of the modes of vibrations are generated in the structure B by external force such as an earthquake, a wind, etc., components close to the natural frequency of the device A in vibrational energy accumulated in the structure B are transferred easily from the structure B to the device A. Accordingly, vibrations can be damped.

Description

Detailed Description of the Invention: "Industrial Application Field - The present invention is directed to a multi-degree-of-freedom dynamic vibration absorption method and a multi-degree-of-freedom dynamic vibration absorption method for suppressing vibrations consisting of a plurality of vibration modes generated in structures due to earthquakes, wind disturbances, etc. This article relates to a vibration absorbing device, and in particular, relates to a multi-degree-of-freedom dynamic vibration absorbing method and a multi-degree-of-freedom dynamic vibration absorbing device that can perform highly efficient vibration suppression that increases the comfort of high-rise structures.

[Prior Art and its Problems 1 Conventionally, the following two types of devices are generally known as dynamic vibration absorbers for suppressing vibrations of structures. One of them is a movable inertial mass installed at a predetermined position of the structure to be damped, and a movable inertial mass installed between the inertial mass and the structure so that the inertial mass can be moved horizontally. Support A17-
It is an active dynamic vibration absorption device equipped with an F-yuator,
The other one is a structure in which a predetermined elastic member and a damper are coupled to the movable inertial mass body, or a passive dynamic vibration absorption device in which the inertial mass body has a pendulum structure.

In the case of active dynamic vibration absorbers, this vibration is controlled in response to the vibrations of the structure, so there is no need to supply all the energy required to absorb the vibrations externally. First, the amount of energy involved is enormous, and current technology can only be applied to relatively light structures. In addition, passive dynamic vibration absorbers reduce the amplitude of specific vibration modes of the structure, so there is no need to supply the energy necessary to absorb vibrations externally, or t2D is only effective in a specific frequency range, and in the case of a wide frequency band such as an earthquake, the reduction effect cannot be expected much.

This invention was made in view of the above circumstances.
Vibration suppression effect on vibrations with multiple vibration modes
It is an object of the present invention to provide a multi-degree-of-freedom dynamic vibration absorbing method and a multi-degree-of-freedom dynamic vibration absorbing device that do not require external supply of energy necessary for absorbing vibrations.

A means to solve a problem.

In order to solve the above problems, the present invention employs the following multi-degree-of-freedom dynamic vibration absorbing method and multi-degree-of-freedom dynamic vibration absorbing device.

Among the second inventions, the multi-degree-of-freedom dynamic vibration absorption method according to claim 1 includes movably installing a plurality of inertial masses at predetermined positions of a structure, and connecting the inertial masses and the structure. and a spring and a damper are provided between each of the inertial mass bodies, and when vibrations consisting of a plurality of vibration modes are excited in the structure described in 11j due to an external force such as an earthquake or wind, the plurality of natural vibrations of the structure are The structure is characterized in that vibrations excited in the structure are suppressed by setting the upper folds of the spring so as to have a natural frequency corresponding to the natural frequency.

The multi-degree-of-freedom dynamic vibration absorption device according to claim 2 is installed at a predetermined position of a structure and absorbs a plurality of vibrations excited in the structure by an external force such as an earthquake or wind. A multi-degree-of-freedom dynamic vibration absorber for suppressing vibrations consisting of modes.The multi-degree-of-freedom dynamic vibration absorber is movable in the horizontal direction; and said structure and C)
and the inertial mass body phase, respectively.
a tamper for suppressing the vibration of the structure;
An elastic member is provided between the inertial mass body and the structure and between the inertial mass bodies, and between the inertial mass body, the structure, and the inertial mass bodies. What's wrong?

Furthermore, the multi-degree-of-freedom dynamic vibration absorption device according to claim 3 is capable of absorbing vibrations consisting of a plurality of vibration modes when suspended in a predetermined position of a structure and excited in the structure by an external force such as an earthquake or wind. The multi-degree-of-freedom dynamic vibration absorber suppresses a plurality of inertial mass bodies suspended from the structure, and a structure between the inertial mass bodies and the structure. The present invention is characterized by a damper provided between each of the inertial mass bodies.

Function: In the multi-freedom, variable vibration damping method and multi-degree-of-freedom dynamic vibration damping device according to the present invention, when vibrations consisting of a plurality of vibration modes are excited in a structure by an external force such as an earthquake or wind, the following effects occur. You're talented. In the multi-degree-of-freedom dynamic vibration absorption method according to claim 1, a spring and a tamper are provided between the inertial mass body and the structure and between the inertial mass bodies. The vibration energy generated in the structure by external forces such as earthquakes and wind is absorbed by these inertial mass bodies and dampers, and horizontal vibrations are suppressed.

In the multi-degree-of-freedom dynamic vibration absorber according to claim 2,
When vibrations consisting of multiple vibration modes are excited in a structure due to an external force such as an earthquake or wind, one elastic member and damper are installed between the inertial mass body and the structure and between the inertial mass bodies. , the vibration energy generated in the structure is absorbed or transferred to the inertial mass body, and vibrations excited in the structure are suppressed.

Furthermore, in the multi-degree-of-freedom dynamic vibration absorber according to claim 3,
When vibrations consisting of multiple modes of vibration are excited in a structure due to an external force such as an earthquake or wind, the inertial mass between the multiple inertial masses suspended from the structure and the said structure may be damaged. The 'P+ and 7- dampers provided between each other absorb vibration energy generated in the structure or transfer it to the inertial mass body, thereby suppressing vibrations excited in the structure.

One example.

Embodiments of the present invention will be described below based on the drawings.

Well, the first aspect of the multi-degree-of-freedom dynamic vibration absorbing device according to claim 2.
This will be explained based on the figure and FIG.

FIG. 1 is a diagram showing a multi-degree-of-freedom dynamic vibration damping device A according to the present invention mounted at a predetermined position on the top B1 of a structure B to be damped.

This multi-degree-of-freedom dynamic vibration absorber A includes a plurality of inertial mass bodies 1 to 3.
, a plurality of dampers 11-13, a plurality of elastic members 21-2
It is roughly composed of 3.

The inertial masses 1 to 3 are rectangular parallelepipeds with large inertia. These inertial mass bodies 1 to 3 are arranged in a straight line at predetermined positions on the top B1 of the structure B, and each is movable in the horizontal direction (horizontal direction in FIG. 1).

The dampers 11-13 and the elastic members 21-23 have a predetermined constant that has a natural frequency corresponding to a plurality of natural frequencies of the structure B, and are used to suppress vibrations of the structure B. It is something. Of these, the damper 11 is a support 31 that projects vertically upward from the neck B1 of the structure B.
and the inertial mass l, one end of which is connected to the support 31,
The other end portions are respectively attached to the inertial mass body l.

The axis and operating direction of this damper II are from the inertial mass body 1 to
This is the same direction of movement as in step 3. Further, the damper 12 is located between the inertial mass body 1 and the inertial mass body 2, and has one end attached to the inertial mass body 1 and the other end attached to the inertial mass body 2. Further, the damper 13 is located between the inertial mass body 2 and the inertial mass body 3, and has one end attached to the inertial mass body 2 and the other end attached to the inertial mass body 3. These dampers! The respective axes and working directions of 2.13 are the same as those of the damper 11.

The elastic member 21 is inserted between the column 31 and the inertial mass body 1, and one end is attached to the column 31 and the other end is attached to the inertial mass body 1. The axis and operating direction of this elastic member 21 are the same as the moving direction of the inertial masses 1 to 3. In addition, the elastic member 22 includes an inertial mass body 1 and an inertial mass body 2.
, and its end is attached to the inertial mass body 1, and the other end is attached to the inertial mass body 2. Further, the elastic member 23 is located between the inertial mass body 2 and the inertial mass body 3,
One end is attached to the inertial mass body 2, and the other end is attached to the inertial mass body 3. These elastic members 22.23
The respective axes and operating directions of the elastic member 21 are the same as those of the elastic member 21.

Next, based on the multi-degree-of-freedom dynamic vibration absorber according to claim 1,
The operation of the multi-degree-of-freedom dynamic vibration absorber A described above will be explained.

When vibrations consisting of a plurality of vibration modes occur in the structure B due to an external force such as an earthquake or wind, vibration energy is accumulated in the structure H. Of this vibration energy, the component near the natural frequency of the Honda multi-degree-of-freedom dynamic vibration absorber A is easily absorbed by the structure B.
to the multi-degree-of-freedom dynamic vibration absorber A, and as a result structure B
to suppress vibrations.

Next, the vibration suppressing effect when the multi-degree-of-freedom dynamic vibration absorbing device A is mounted at a predetermined position on the top of the structure B to be damped will be described.

Figure 2 shows the vibration suppression effect in terms of response magnification.
This is a graph of the frequency (rad/5ec) dependence of response magnification. The curve shown by the broken line is the response magnification of a normal structure B that is not equipped with a multi-degree-of-freedom dynamic vibration absorber A,
The curve shown by the solid line is the response magnification when the multi-degree-of-freedom dynamic vibration absorber A is mounted on the structure B.

In this figure, it is clear that when the multi-degree-of-freedom dynamic vibration absorber A is mounted on the structure B, the response magnification is significantly reduced compared to when the structure B is used normally. Moreover, since the vibration is uniformly reduced for different values of vibration frequency, it is clear that it has a good vibration suppression effect over a wide frequency band.

As explained in detail above, the multi-degree-of-freedom dynamic vibration absorber A includes a plurality of inertial masses 1 to 3 that are installed so as to be movable in the horizontal direction, and an inertial mass between the inertial mass I and the structure B. 1.2
Dampers 11 to 11 installed between (2, 3)
13, and an elastic member 2 inserted between the inertial mass body I and the structure B and between the inertial mass body 1.2 (2, 3), respectively.
1 to 23, it is applied to the structure 13 by operating in the axial direction at natural frequencies corresponding to the plurality of natural frequencies of the structure B, thereby generating f- a plurality of vibration modes. Effectively absorbs the vibration energy of
The amplitude of each vibration mode in the horizontal direction can be significantly reduced, and horizontal vibrations can be effectively damped.

Therefore, it is possible to effectively suppress vibrations generated in the structure B that are composed of a plurality of vibration modes.

Next, regarding the multi-degree-of-freedom dynamic vibration absorbing device according to claim 3, a third
This will be explained based on the diagram.

FIG. 3 is a diagram showing a state in which the multi-degree-of-freedom dynamic vibration absorber E according to the present invention is installed on the top F1 of the vibration damping structure F and suspended at a predetermined position on the top of the structure G. be.

This multi-degree-of-freedom dynamic vibration absorber consists of a plurality of parts, 〒member 41
．． 42, a plurality of inertial mass bodies 51-53, and a plurality of dampers 61-63.

The suspension members 41 and 42 are bendable string-like members extending vertically downward from the lower surface of the top 01 of the structure G, and are made of, for example, steel wire (δ).

The inertial mass bodies 51 to 53 are plate-shaped with large inertia. These inertial mass bodies 51 to 53 are arranged at equal intervals in the vertical direction between the suspension members 41 and 42,
One end of each is attached to a suspension member 41, the other end of each is attached to a suspension member 42, and the length is set to have a natural frequency corresponding to the natural frequency of the structure F. Ru.

Among the dampers 61 to 63, the damper 61 is located between the top Gl bottom surface 71 of the structure G and the inertial mass body 51, and has one end attached to the bottom surface 71 and the other end attached to the inertial mass body 51. There is. The axis and operating direction of this damper 61 are the same as the moving direction of the inertial mass body 51. Also,
The damper 62 is located between the inertial mass body 51 and the inertial mass body 52, and has one end attached to the inertial mass body 51 and the other end attached to the inertial mass body 52. Further, the damper 63 is located between the inertial mass body 52 and the inertial mass body 53, with one end attached to the inertial mass body 52 and the other end attached to the inertial mass body 5.
The respective axes and operating directions of these dampers 62 and 63 are attached to the damper 6.
1 axis and operating direction.

With the above configuration, a multi-degree-of-freedom dynamic vibration absorption device E having natural frequencies corresponding to a plurality of natural frequencies of the structure F can be obtained.

Next, based on the multi-degree-of-freedom dynamic vibration absorption method according to claim 1,
The operation of the multi-degree-of-freedom dynamic vibration absorber E will be explained.

When vibrations consisting of a plurality of vibration modes occur in a structure due to an external force such as an earthquake or wind, vibration energy is accumulated in the structure. Of this vibration energy, the natural frequency and side components of the multi-degree-of-freedom dynamic vibration absorber 1 easily transfer from the structure F to the multi-degree-of-freedom dynamic vibration absorber E, and as a result, the components of the multi-degree-of-freedom dynamic vibration absorber 1. Suppress vibration.

Between the inertial mass bodies 51 and 52 (52, 53),
- In the same way as between the structural member G and the inertial mass body 5I, the vibration energy consisting of a plurality of vibration modes applied to the damper 62 (63) is transmitted to the inertial mass body 51° 52 (52, 53).
) is absorbed by operating in the axial direction, and horizontal vibrations are suppressed.

Regarding the vibration suppression effect when this multi-degree-of-freedom dynamic vibration absorption device E is suspended from the structure G at the top of the structure F to be damped,
Since it is exactly the same as the multi-degree-of-freedom dynamic vibration absorber A listed above, the explanation will be omitted.

As explained in detail above, the multi-degree-of-freedom dynamic vibration absorber E includes a plurality of inertial mass bodies 51 to 51 suspended from the structure G of the structure F.
53, and dampers 61 to 63 provided between the inertial mass body 51 and the structure G and between the inertial mass bodies 51, 52 (52, 53), respectively.
By operating the inertial mass bodies 51 to 53 in the axial direction at a natural frequency corresponding to each of the plurality of natural frequencies of the structure F, the vibration energy having a plurality of vibration modes applied to the structure F is made effective. , the amplitude of each vibration mode in the horizontal direction can be significantly reduced, and horizontal vibration can be effectively damped.

Therefore, vibrations generated in the structure F, which are composed of a plurality of vibration modes, can be effectively suppressed.

Next, in order to demonstrate the effects of the present invention, the results of an immunization analysis conducted using the present invention will be described.

The response magnification was numerically calculated using a vibration model with four mass points as shown in Figure 4. In this vibration model, a multi-degree-of-freedom dynamic vibration absorption device consisting of two mass points is placed on top of a structure consisting of two mass points, and dampers and elastic members are provided between the structure and the mass points and between the mass points. It has an f-co configuration. Here, XI to X4 are the coordinates of each mass point, and (d'z/dt2) is the acceleration of the ground.

In this numerical calculation, the equation of motion of this vibration model including the multi-degree-of-freedom dynamic vibration absorber is expressed by the following equation.

[ml (d'x/ dt') + Ic] (dx/
dt) ”, [k] (x)−-[mI(I)(
d2z/dt') -・= (1) (x) - (XI,
X2. X3. X4)Twhere, [ll11, [c]
, [k] are the mass matrix, damping matrix, and stiffness matrix, respectively, h) is the displacement vector, and d”
Z/dt2 is ground motion acceleration.

The respective values of the mass matrix, damping matrix, and stiffness matrix used in the above numerical calculations are shown below.

1.0 0.5 0.025i 0.0+ 0 0 0
0.005 0 00 0.
005 0 0 0 0.0025D -0.025 The weight of the multi-degree-of-freedom dynamic vibration absorber is 5% of the structure whose vibration is to be suppressed, and the damping constant of the structure is the first natural frequency. 1%, and the damping constant of the multi-degree-of-freedom dynamic vibration absorber is assumed to be 10% at the first natural frequency.

FIG. 5 shows the results of the above simulation analysis, and is a graph representing the dependence of the acceleration response magnification on the frequency (rad/5eC). The curve shown by the broken line is the acceleration response multiplier at the top of a normal structure without a multi-degree-of-freedom dynamic vibration absorber installed, and the curve shown by the solid line is the acceleration response multiplier for the top of a structure with a multi-degree-of-freedom dynamic vibration absorber installed at the top of the structure. This is the acceleration response magnification.

In this figure, it can be seen that when a multi-degree-of-freedom dynamic vibration absorber is mounted on the top of a structure, the acceleration response magnification is significantly reduced compared to when a normal structure is used. especially,
Since the acceleration response magnification is significantly reduced not only in the first-order natural vibration mode but also in the second-order natural vibration mode, it is clear that it has a good vibration suppression effect for a plurality of natural vibration modes.

As described above, the multi-degree-of-freedom dynamic vibration absorption method and multi-freedom method have a good vibration suppression effect on vibrations that have multiple vibration modes, and do not require external supply of the energy necessary to absorb the vibrations. It becomes possible to provide a dynamic vibration absorbing device.

"Effects of the Invention" The multi-degree-of-freedom dynamic vibration absorption method according to claim 1 of the present invention includes movably disposing a plurality of inertial masses at predetermined positions of a structure.
A spring and a damper are provided between the inertial mass body and the structure and between the inertial mass bodies, so that vibrations consisting of a plurality of vibration modes are excited in the structure by an external force such as an earthquake or wind. In this case, we decided to suppress the vibrations excited in the structure by setting the 7\ne and the damper so that it has a natural frequency corresponding to a plurality of natural frequencies of the structure. Among the vibration energy applied to the structure, vibration energy in a specific vibration mode can be effectively absorbed.

Therefore, it is possible to effectively suppress vibrations generated in the structure that are composed of a plurality of vibration modes, and it is possible to obtain a good vibration suppression effect for multi-order natural vibration modes.

Further, the multi-degree-of-freedom dynamic vibration absorbing device according to claim 2 can be installed at a predetermined position of a structure and generate 1t! ! Earthquakes, wind, etc. a plurality of inertial masses that are freely installed; a damper between the inertial masses and the structure; a damper between the inertial masses and the structure; and a damper between the inertial masses and the structure; Since the elastic member is provided between the inertial mass body, the structure, and the inertial mass bodies, the vibration mode is applied to the structure and has one or more vibration modes. By effectively absorbing vibration energy and significantly reducing the amplitude of each vibration mode in the horizontal direction, horizontal vibrations can be effectively damped. Therefore, it is possible to effectively suppress vibrations consisting of a plurality of vibration modes ζ generated in the structure.

Further, the multi-degree-of-freedom dynamic vibration absorption device according to claim 3 is configured to suppress vibrations consisting of a plurality of vibration modes that are suspended in a predetermined position of a structure and excited in the structure by external forces such as earthquakes and wind. A multi-degree-of-freedom dynamic vibration absorber, the multi-degree-of-freedom dynamic vibration absorber comprising: a plurality of inertial mass bodies suspended from the structure;
Since a damper is provided between the inertial mass body and the structure and between each of the inertial mass bodies, the damper is provided at a natural frequency corresponding to each of the plurality of natural frequencies of the structure. By operating in the axial direction, it effectively absorbs vibration energy with multiple vibration modes applied to the structure, and significantly reduces the amplitude of each vibration mode in the horizontal direction. can be effectively attenuated. Therefore, it is possible to effectively suppress vibrations generated in the structure that are composed of a plurality of vibration modes, and it is possible to obtain a good vibration suppression effect for multi-order natural vibration modes.

As described above, a multi-degree-of-freedom dynamic vibration absorption method and a multi-degree-of-freedom dynamic vibration absorption method that have a good vibration suppression effect on vibrations having multiple vibration modes and do not require external supply of the energy necessary to absorb vibrations. It becomes possible to provide a dynamic vibration absorber.

[Brief explanation of drawings]

1 and 2 are diagrams showing an embodiment of claim 2 of the present invention, in which FIG. 1 is a schematic configuration diagram of a multi-degree-of-freedom dynamic vibration absorber, and FIG. 2 is a multi-degree-of-freedom dynamic vibration absorbing device. A graph showing the vibration suppression effect of the dynamic vibration absorber, FIG. 3 is a schematic configuration diagram of a multi-degree-of-freedom dynamic vibration absorber which is an embodiment of claim 3 of the present invention, and FIG. 4 is a graph showing the vibration suppression effect of the present invention. FIG. 5, which is a schematic diagram of the vibration model used, shows the vibration suppression effect of the multi-degree-of-freedom dynamic vibration damping device based on the numerical analysis of the present invention. multi-degree-of-freedom dynamic vibration absorber, structure, inertial mass body, damper elastic member, multi-degree-of-freedom dynamic vibration absorber, structure, 1-3 21-23 ], 4 51-53 rolling member, inertial mass body, 1- 6 Dunbar

Claims (3)

[Claims] (1) A plurality of inertial masses are movably provided at predetermined positions on a structure, and springs and dampers are provided between the inertial masses and the structure and between each of the inertial masses to prevent earthquakes. The spring and damper are set to have a natural frequency corresponding to a plurality of natural frequencies of the structure when vibrations consisting of a plurality of vibration modes are excited in the structure by an external force such as wind. A multi-degree-of-freedom dynamic vibration absorption method characterized by suppressing vibrations excited in the structure. (2) A multi-degree-of-freedom dynamic vibration absorption device installed at a predetermined position of a structure to suppress vibrations consisting of a plurality of vibration modes excited in the structure by external forces such as earthquakes and wind, the multi-degree-of-freedom dynamic vibration absorption device The vibration damping device includes a plurality of inertial masses installed horizontally movably, and installed between the inertial masses and the structure and between the inertial masses, and absorbs vibrations of the structure. A multi-degree-of-freedom dynamic vibration absorbing device comprising: a damper for suppressing vibration; and an elastic member between the inertial mass body and the structure and between the inertial mass bodies. (3) A multi-degree-of-freedom dynamic vibration absorption device that is suspended at a predetermined position of a structure and suppresses vibrations consisting of a plurality of vibration modes excited in the structure by external forces such as earthquakes and wind, The degrees of freedom dynamic vibration absorption device includes a plurality of inertial masses suspended from the structure, and dampers provided between the inertial masses and the structure and between the inertial masses. A multi-degree-of-freedom dynamic vibration absorber characterized by: