JP7304109B1 - damping device - Google Patents

Abstract

A pendulum type vibration damping device is provided in which the natural frequency can be easily adjusted for each movable direction. SOLUTION: First and second suspension members 11 and 12 are both attached to a structure 81 to be damped, and passively swing a mass body 2 with vibration of the structure 81. Suspend vertically so that it can be moved. Both the first and second elastic members 31 and 32 are arranged so as to be inclined with respect to the vertical direction, and are arranged between the structure 81 and the mass body 2, or between the structure 81 and the first and second elastic members 31 and 32. It is arranged so as to connect between the second hanging members 11 and 12 . The first and second elastic members 31 and 23 are both arranged in a vertical plane, and are arranged symmetrically with respect to a vertical imaginary axis of symmetry. [Selection drawing] Fig. 13

Description

The present invention relates to a damping device for controlling horizontal vibrations generated in structures such as buildings and bridges. More specifically, the present invention relates to a pendulum type vibration damping device that facilitates adjustment of the natural frequency for each movable direction.

When structures such as buildings and bridges are subject to wind loads from typhoons, or vibrations caused by earthquake loads or traffic loads, these vibrations not only pose a safety problem for structures, but also This will make the user feel uncomfortable. Attempts have therefore been made to suppress or minimize vibrations using damping devices.

A tuned mass damper (TMD) is a typical damping device for structures. The TMD has a movable mass and a damper that passively vibrate with the vibration of the structure, and the vibration can be controlled by installing the TMD on the structure.

Figure 1 shows a vibration dynamics model of a horizontally vibrating structure and TMD. The movable mass (mass m _T ) is about several percent of the mass m _S of the structure. For example, when a structure shakes due to factors such as wind load and seismic load, the TMD will operate while shaking in sync with it. At this time, the vibration energy is absorbed by the damper _CT provided in the TMD, and the vibration of the structure is also suppressed. In order to effectively exert such a damping effect, it is necessary to set the natural frequencies of the structure and TMD to be almost equal (for example, the frequency ratio is about 98% to 99%). .

The vibration damping device is classified into a vertical vibration damping device and a horizontal vibration damping device according to the vibration direction of the structure, and the horizontal vibration damping device will be described below. Horizontal vibration damping devices are classified into a slide type and a pendulum type. In the following, as shown in FIG. The structure of the pendulum type vibration damping device will be described.

In general, structures such as buildings and bridges have various natural frequencies depending on the direction of vibration. That is, when a high-rise building vibrates horizontally, it is common that the natural frequency of swinging in the front-rear direction is not equal to the natural frequency of swinging in the left-right direction. The eigenfrequency of the bridge main tower is not the same when it sways in the direction of the bridge axis and when it sways in the direction perpendicular to the axis.

As mentioned above, the natural frequency of the TMD is set approximately equal to the natural frequency of the structure. Therefore, the natural frequency of the pendulum-type damping device must also be set substantially equal to the natural frequency of the structure.

On the other hand, the natural frequency of the movable mass in a pendulum-type vibration damping device, that is, a pendulum-type TMD, depends on the length of the vibrating pendulum (specifically, the length of the hanging member). That is, the natural frequency is lowered in proportion to the square root of the reciprocal of the pendulum length. In a pendulum TMD, one or more pendulums of the same length will be used, which means that for pendulum TMDs operating in the horizontal direction, they have the same natural frequency regardless of the direction of motion. .

However, as described above, structures such as buildings and bridges generally have different natural frequencies depending on the direction of vibration. Therefore, in this case, the control effect of the pendulum type vibration damping device is remarkably lowered depending on the vibration direction.

In order to solve the above problems, techniques shown in FIGS. 3 to 7 have been proposed. This technique is a pendulum-type vibration damping device that operates in a horizontal direction, allowing the entire length of the pendulum to move in one direction, and constraining a fixed length of the pendulum to not move in the other direction. The natural frequency can be set differently depending on the vibration direction of the damping device. That is, in the pendulum type vibration damping device that operates horizontally in the X direction and the Y direction by suspending the movable mass 200 with the suspension member 100 as shown in FIG. Position the equipment properly. Then, as shown in FIG. 6, when the pendulum type TMD operates in the X direction, the pendulum operates only for a certain length (L2) by the vibration frequency adjustment device 400. FIG. On the other hand, as shown in FIG. 7, when the pendulum type TMD is movable in the Y direction, the pendulum is not affected by the frequency adjustment device 400, so the full length (L1+L2) of the pendulum operates.

Therefore, the natural frequency of the movable mass 200 can be set differently depending on the vibrating direction. However, when adjusting the natural frequency of the pendulum using such a system, friction between the pendulum and the frequency adjusting device 400 becomes a problem. Such friction is not large when the pendulum moves in the Y direction, but when the pendulum moves in the X and Y directions at the same time (i.e., in a direction having components in both directions), a large frictional force is generated. will occur. Even if a low-friction material is used for the frequency adjuster 400, at least several percent of the friction is expected.

As another prior art, a pendulum-type TMD that operates in the horizontal direction by providing a rigid device 500 as shown in FIG. This technique allows the full length of the pendulum to move in one direction, constrains a fixed length of the pendulum in the other direction, and creates different natural frequencies depending on the direction of vibration of the movable mass 200. can be set to

That is, in the pendulum type vibration damping device that operates horizontally in the X direction and the Y direction as shown in FIG. Install. Then, as shown in FIG. 10, the pendulum can be actuated by a certain length (L1+L3) in the X direction. On the other hand, as shown in FIG. 11, the full length (L1+L2+L3) of the pendulum can be operated in the Y direction. In this manner, the natural frequency of the movable mass 200 can be set differently depending on the direction of vibration. However, when the natural frequency of the movable mass 200 is adjusted by such a system, the rigid body device 500 installed on the pendulum may perform independent motion such as buckling in addition to the pendulum motion, thereby degrading the damping performance. There is Moreover, there is a drawback that it is very difficult to finely adjust the natural frequency in the X direction.

Furthermore, in Japanese Unexamined Patent Application Publication No. 2002-100000, the natural frequencies in the X and Y directions are adjusted by providing inclined springs 601 and dampers 602 in the X and Y directions as shown in FIG. In this technique, an inclined spring is fixed to the center of gravity (G) or line of gravity of the movable mass 200 so that the suspension member 100 is fixed to the height (P) of the center of gravity of the movable mass. It's becoming

If the tilt spring is not fixed to the center of gravity of the movable mass, when the pendulum type TMD vibrates simultaneously in the X and Y directions, the movable mass 200 moves in the torsional direction, resulting in a large damping effect. The above arrangement eliminates this problem, as it tends to reduce it. In addition, since the springs are not arranged symmetrically in the X direction and the Y direction, and the spring 601 is arranged on one side and the damper 602 on the other side, the springs are not fixed on the gravity center point (G) of the movable mass 200 or on the gravity center line. and another cause of torsional motion of the moving mass. Furthermore, with this technology, the vibration frequency in both the X and Y directions is set higher than the TMD vibration frequency due to the length of the pendulum. There are required shortcomings.

JP-A-7-238987

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pendulum-type vibration damping device that eliminates the above-described drawbacks and facilitates adjustment of the natural frequency for each movable direction. .

Means for solving the above problems can be described as the following items.

(Item 1)
It comprises first and second hanging members, a mass, and an elastic mechanism,
Both the first and second suspension members are attached to a structure to be damped so that the mass body can passively swing with the vibration of the structure. It is configured to hang vertically,
The elastic mechanism comprises first and second elastic members,
Both the first and second elastic members are arranged so as to be inclined with respect to the vertical direction, and are arranged between the structure and the mass body, or between the structure and the first and second elastic members. It is arranged so as to connect between the 2 hanging materials,
The pendulum type is characterized in that both the first and second elastic members are arranged in a vertical plane and arranged symmetrically with respect to a vertical imaginary axis of symmetry. damping device.

(Item 2)
The pendulum type vibration damping device according to item 1, wherein the vertical plane is set along a direction in which the frequency is to be adjusted.

(Item 3)
3. The pendulum type vibration damping device according to item 1 or 2, wherein the structure is a ceiling surface of a structure or a support that is fixed to the structure and capable of supporting the first and second hanging members.

(Item 4)
Both the first and second hanging members are arranged so as to be vertical in a stationary state,
3. A pendulum type vibration damping device according to item 1 or 2.

(Item 5)
A vibration damping method, comprising damping the structure using the pendulum type damping device according to item 1.

(Item 6)
The control according to item 5, further comprising a step of adjusting the natural frequency of the mass body that swings in the vertical plane by adjusting the inclination angle and/or the elastic modulus of the first and second elastic members. swing method.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the pendulum-type vibration damping apparatus which can easily adjust the natural frequency for every movable direction.

FIG. 4 is a diagram showing a mechanical model of a structure and TMD with respect to horizontal vibration; FIG. 10 is a schematic explanatory diagram of a conventional pendulum type vibration damping device; 1 is a schematic explanatory diagram of a conventional pendulum type vibration damping device that operates in the X and Y directions; FIG. FIG. 2 is a schematic explanatory diagram of a conventional pendulum-type damping device using a frequency adjusting device; FIG. 5 is an explanatory view of FIG. 4 viewed from the side; FIG. 5 is an explanatory diagram showing a state in which the device of FIG. 4 operates in the X direction; FIG. 5 is an explanatory diagram showing a state in which the device of FIG. 4 operates in the Y direction; FIG. 10 is a schematic explanatory diagram of a conventional pendulum-type vibration damping device using another frequency adjusting device; FIG. 9 is an explanatory diagram of FIG. 8 viewed from the side; FIG. 9 is an explanatory diagram showing a state in which the device of FIG. 8 operates in the X direction; FIG. 9 is an explanatory diagram showing the state in which the apparatus of FIG. 8 operates in the Y direction; FIG. 10 is a schematic explanatory diagram of a conventional pendulum-type vibration damping device using still another frequency adjusting device. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which added the parameter to the schematic front view of the pendulum-type damping apparatus which concerns on 1st Embodiment of this invention. FIG. 14 is a schematic perspective view for explaining the arrangement state of hanging members in the device of FIG. 13; FIG. 14 is an explanatory diagram with parameters, showing the device of FIG. 13 operating in the X direction; FIG. 14 is a schematic explanatory diagram in which description of parameters is omitted from FIG. 13; FIG. 14 is a schematic explanatory view of the device of FIG. 13 viewed from the side; FIG. 17 is an explanatory diagram showing a state in which the device of FIG. 16 operates in the X direction; FIG. 17 is an explanatory diagram showing a state in which the apparatus of FIG. 16 operates in the Y direction; FIG. 5 is a schematic explanatory diagram of a pendulum type vibration damping device according to a second embodiment of the present invention viewed from the front; FIG. 21 is a schematic explanatory view of the device of FIG. 20 viewed from the side; FIG. 11 is a schematic explanatory diagram of a pendulum-type vibration damping device according to a third embodiment of the present invention as viewed from the front; FIG. 11 is a schematic explanatory diagram of a pendulum-type vibration damping device according to a fourth embodiment of the present invention as viewed from the front; FIG. 11 is a schematic explanatory diagram of a pendulum-type vibration damping device according to a fifth embodiment of the present invention as viewed from the front; FIG. 11 is a schematic explanatory diagram of a pendulum-type vibration damping device according to a sixth embodiment of the present invention as viewed from the front; FIG. 11 is a schematic explanatory diagram of a pendulum type vibration damping device according to a seventh embodiment of the present invention as viewed from the front; FIG. 21 is a schematic explanatory diagram of a pendulum type vibration damping device according to an eighth embodiment of the present invention as viewed from the front;

A pendulum type vibration damping device according to a first embodiment of the present invention (hereinafter sometimes simply referred to as "vibration damping device" or "device") will now be described with reference to FIGS. 13 to 19. FIG.

(Configuration of this embodiment)
The vibration damping device of this embodiment has a pendulum mechanism 1, a mass body 2, and an elastic mechanism 3 as main components.

Specifically, the pendulum mechanism 1 of this embodiment is composed of first to fourth hanging members 11 to 14 (see FIG. 14). Note that the elastic mechanism 3 is omitted in FIG. 14 for ease of viewing.

(pendulum mechanism)
All of the first to fourth suspension members 11 to 14 are attached to the structure 81 to be damped, and the mass 2 can passively swing with the vibration of the structure 81. It is configured to be hung vertically. Here, the structure 81 is, for example, a support (a so-called frame) that is fixed to the structure 8 such as a building or the ground and capable of supporting a hanging member, but is not limited thereto, such as a ceiling surface of a building, a lower surface of a bridge, or the like. , any object to be damped.

All of the first to fourth hanging members 11 to 14 are arranged so as to be vertical in a stationary state. These hanging members 11 to 14 are composed of wires or rods, for example, but the same hanging members as in the case of various ordinary pendulum mechanisms can be used.

(mass body)
The mass body 2 may be an appropriate weight. The mass 2 functions as a so-called movable mass in TMD. The motion of the mass body 2 based on the dynamic model will be described later.

(elastic mechanism)
The elastic mechanism 3 of this embodiment has first and second elastic members 31 and 32 . Both the first and second elastic members 31 and 32 are arranged so as to be inclined with respect to the vertical direction, and are arranged so as to connect the structure 81 and the mass body 2 . Further, the first and second elastic members 31 and 32 are both arranged in a virtual vertical plane and are symmetrical with respect to a vertical virtual axis of symmetry 5 (see FIG. 13). are placed. This virtual vertical plane is set along the direction in which the natural frequency is to be adjusted ( the x direction in this example). As the first and second elastic members 31 and 32 in this embodiment, for example, springs and rubber can be used, but not limited to these, various mechanisms having necessary elastic modulus and strength can be used. .

(Theoretical background of the damping device of the present embodiment)
Here, the theoretical background of the vibration damping device of this embodiment will be described with reference to FIGS. 13 and 15. FIG.

As shown in FIG. 13, the pendulum length: l
Mass of mass (movable mass): m
Elastic modulus of the first and second elastic members: k
Angle between one elastic member and vertical direction (virtual axis of symmetry): φ ₀
Length of one elastic member: L ₀
Distance between both ends of elastic member (distance in horizontal direction): b
and

For example, when the mass body 2 of the vibration damping device of this embodiment moves horizontally (moves in the x direction) by an angle θ as shown in FIG. can be expressed as follows.

Here, since the formula (1-3) is a non-linear formula, ΔL can be expressed as follows by applying the following Taylor Series to lead to a linear formula.

Based on the above formula, the equation of motion and natural frequency f of the mass body 2 shown in the figure are derived as follows. Here, g indicates gravitational acceleration.

As can be seen from equation (3-4), in a pendulum-type vibration damping device having a pendulum length l and a movable mass _m , the mass The natural frequency of body 2 can be increased. That is, it becomes possible to adjust the natural frequency. Here, the distance b is determined according to the position of the lower end of the elastic member. Although FIG. 15 shows an example in which the mass body 2 moves to the right in the figure, the movement to the left in the figure is also the same in principle, except that the left and right are reversed.

In conclusion, the natural frequency of the mass body 2 of this embodiment increases in proportion to the square root of the elastic modulus k. Also, it can be seen that the natural frequency increases as b/L ₀ , that is, the inclination angle of the elastic members 31 and 32 increases.

(Operation of this embodiment)
Based on the above theoretical background, the operation of the vibration damping device of this embodiment will be described with further reference to FIGS. 16 to 19. FIG.

First, with respect to vibration in the x-direction shown in FIGS. 16 and 18, as described in the theoretical background, the natural frequency can be increased according to parameters such as the elastic modulus and tilt angle of the elastic member.

On the other hand, regarding the vibration in the y direction shown in FIGS. can be ignored. Therefore, the mass 2 operates in the y-direction at a natural frequency determined by the length of the suspension member.

That is, as described above, according to the vibration damping device of the present embodiment, different natural frequencies can be obtained in the x direction and the y direction. Therefore, if the structure to be damped has a high natural frequency in the x direction and a low natural frequency in the y direction, by installing the vibration damping device of the present embodiment so as to match it, A good damping effect can be obtained respectively.

Furthermore, according to the vibration damping device of this embodiment, the elastic modulus k of the first and second elastic members 31 and 32 can be adjusted by a very simple method such as exchanging the springs. Also, the angle between the first and second elastic members 31 and 32 and the vertical can be easily adjusted.

Since the vibration damping device of this embodiment does not generate frictional resistance unlike the conventional vibration damping device shown in FIGS. 4 to 7, a sufficient vibration control effect can be expected even for small vibrations. In addition, since a rigid device such as the conventional vibration damping device shown in FIGS. 8 to 11 is not required, it is possible to prevent unstable phenomena such as buckling. Furthermore, in this embodiment, since the pair of elastic members 31 and 32 are arranged symmetrically, abnormal phenomena such as torsional behavior can be prevented even if the elastic members 31 and 32 are not fixed to the center of gravity of the mass body 2. It is possible to obtain a high damping effect.

(Second embodiment)
Next, a vibrating device according to a second embodiment of the invention will be described with reference to FIGS. 20 and 21. FIG. In the description of the second embodiment, the same reference numerals are used for components that are basically the same as those of the first embodiment described above to avoid duplication of description.

In this second embodiment, a plurality of elastic mechanisms 3 are provided parallel to each other (see FIG. 21). The configuration of each elastic mechanism 3 is the same as that of the first embodiment (see FIG. 20).

In the vibration device of the second embodiment, as in the first embodiment, the natural frequency in the x direction (see FIG. 20) can be increased. The natural frequency in the y-direction (see FIG. 21) is almost unchanged.

Since the apparatus of the second embodiment is provided with a plurality of elastic mechanisms 3, there is an advantage that twisting of the mass body 2 can be reliably prevented. Therefore, it is possible to reliably adjust the natural frequency.

Other configurations and advantages of the vibrating device of the second embodiment are basically the same as those of the above-described first embodiment, so further detailed description will be omitted.

(Third embodiment)
Next, a vibrating device according to a third embodiment of the invention will be described with reference to FIG. In the description of the third embodiment, the same reference numerals are used for components that are basically the same as those of the first embodiment described above to avoid duplication of description.

In the third embodiment, the first and second elastic members 31 and 32 are mounted on the upper surface of the mass body 2 with narrower intervals between the ends (lower ends). In the device of the third embodiment, the inclination angles of the first and second elastic members 31 and 32 are smaller than those of the device of the first embodiment. The frequency will be lower than the device of the first embodiment.

Other configurations and advantages of the vibrating device of the third embodiment are basically the same as those of the above-described first embodiment, so further detailed description will be omitted.

(Fourth embodiment)
Next, a vibrating device according to a fourth embodiment of the invention will be described with reference to FIG. In the description of the fourth embodiment, the same reference numerals are used for components that are basically the same as those of the first embodiment described above to avoid duplication of description.

In this fourth embodiment, the upper ends of the first and second elastic members 31 and 32 are spaced apart. In this example, the upper ends of the first and second elastic members 31 and 32 are positioned outside the upper ends of the hanging members 11 and 12 . However, it is possible to arrange the upper ends of the first and second elastic members 31 and 32 inside the upper ends of the hanging members 11 and 12 .

According to the vibration damping device of the fourth embodiment, there is an advantage that it is easy to install even if a storage space is created between hanging members and there is a projection from the ceiling surface. Moreover, there is also the advantage that restrictions on the inclination angles of the elastic members 31 and 32 are reduced.

Other configurations and advantages of the vibrating device of the fourth embodiment are basically the same as those of the above-described first embodiment, so further detailed description will be omitted.

(Fifth embodiment)
Next, a vibrating device according to a fifth embodiment of the invention will be described with reference to FIG. In the description of the fifth embodiment, the same reference numerals are used for components that are basically the same as those of the first embodiment described above to avoid duplication of description.

In this fifth embodiment, the first and second elastic members 31 and 32 are arranged to cross each other. It is preferable that the first and second elastic members 31 and 32 are made of a material or constructed so that their elasticity is not mutually hindered by interference.

Other configurations and advantages of the vibrating device of the fifth embodiment are basically the same as those of the first embodiment, so further detailed description will be omitted.

(Sixth embodiment)
Next, a vibrating device according to a sixth embodiment of the invention will be described with reference to FIG. In the description of the sixth embodiment, the same reference numerals are used for components that are basically the same as those of the first embodiment described above to avoid duplication of description.

In this sixth embodiment, the lower ends of the first and second elastic members 31 and 32 are attached to intermediate positions of the hanging members 11 and 12. As shown in FIG. Thus, in the sixth embodiment, the first and second elastic members 31 and 32 connect the structure 81 and the hanging member. Also, the upper ends of the first and second elastic members 31 and 32 are attached to the structure 81 while being spaced apart from each other. Advantages similar to those of the fourth embodiment can be obtained in the sixth embodiment.

Other configurations and advantages of the vibrating device of the sixth embodiment are basically the same as those of the above-described first embodiment, so further detailed description will be omitted.

(Seventh embodiment)
Next, a vibrating device according to a seventh embodiment of the invention will be described with reference to FIG. In the description of the seventh embodiment, the same reference numerals are used for components that are basically the same as those of the first embodiment described above to avoid duplication of description.

In this seventh embodiment, the lower ends of the first and second elastic members 31 and 32 are attached to intermediate positions of the hanging members 11 and 12. As shown in FIG.

Other configurations and advantages of the vibrating device of the seventh embodiment are basically the same as those of the above-described first embodiment, so further detailed description will be omitted.

(Eighth embodiment)
Next, a vibrating device according to an eighth embodiment of the present invention will be described with reference to FIG. In the description of the eighth embodiment, the same reference numerals are used for components that are basically the same as those of the first embodiment described above to avoid duplication of description.

In this eighth embodiment, the upper ends of the first and second elastic members 31 and 32 are attached to the lower ends of projecting portions 82 projecting downward from the structure 81 .

Other configurations and advantages of the vibrating device of the eighth embodiment are basically the same as those of the above-described first embodiment, so further detailed description will be omitted.

In addition, the contents of the present invention are not limited to the above embodiments. The present invention allows various changes to be made to the specific configuration within the scope of the claims.

For example, in each of the above-described embodiments, four hanging members as shown in FIG. 3 are used, but the number of hanging members may be two or more. However, it is necessary that the mass body 2 can swing at least in the X direction and the Y direction. When there are two hanging members, the first and second elastic members 31 and 32 are arranged in a vertical plane including any two hanging members.

1 pendulum mechanisms 11 to 14 first to fourth hanging members 2 mass body 3 elastic mechanisms 31 and 32 first and second elastic members 5 virtual axis of symmetry 8 structure 81 structure 82 protrusion

Claims (6)

It comprises first and second hanging members, a mass, and an elastic mechanism,
Both the first and second suspension members are attached to a structure to be damped so that the mass body can passively swing with the vibration of the structure. It is configured to hang vertically,
The elastic mechanism comprises first and second elastic members,
Both the first and second elastic members are arranged so as to be inclined with respect to the vertical direction, and are arranged between the structure and the mass body, or between the structure and the first and second elastic members. It is arranged so as to connect between the 2 hanging materials,
and the first and second elastic members are both arranged in a vertical plane and arranged symmetrically with respect to a vertical imaginary axis of symmetry ,
The vertical plane is set along the x direction, which is the direction in which the frequency is to be adjusted,
The pendulum type vibration damping device, wherein the mass body is passively swingable by the first and second hanging members in the y direction intersecting with the x direction. 2. The pendulum type vibration damping device according to claim 1, wherein the mass body is swingable in the y direction at a frequency determined by the length of the suspension member. The pendulum type vibration damping device according to claim 1 or 2, wherein the structure is a ceiling surface of the structure or a support that is fixed to the structure and capable of supporting the first and second hanging members. . Both the first and second hanging members are arranged so as to be vertical in a stationary state,
The pendulum type vibration damping device according to claim 1 or 2. A vibration damping method comprising damping the structure using the pendulum type damping device according to claim 1 . 6. Damping of the structure is performed by aligning the x direction with a direction in which the natural frequency of the structure is high and the y direction with a direction of the structure with a low natural frequency. The damping method described in .

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