JP2009174677A - Vibration damping mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective and proper damping mechanism that effectively dampens the vibration of various structures (floor and beam of a building for example) with a simple structure. <P>SOLUTION: This vibration damping mechanism A is provided between two structures (floors 1, 2) that are vibrated relatively in the directions of contacting or separating from each other and reduces the relative vibration in the direction of contacting or separating from each other that occurs to those structures, and is structured with a rotational inertia mass damper 3, which is connected to either one of the structures, and a plate material 4 as a spring element, which is connected in series to the mass damper and connected to the other structure. The center portion of the plate material is connected to the mass damper, and both end portions of the plate material to the other structure. The positions of the connection points of both end portions of the plate material are made variable, so that the rigidity of the plate material is adjusted by adjusting the distance between both connection points. As a damping element 14, a viscoelastic material is laminated integrally on the plate material. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration damping mechanism for reducing vibrations in various structures, and more particularly to a vibration damping mechanism suitably applied to reduce the vertical vibration of a building floor or beam as a vibration control target.

The floors and beams of buildings may cause vertical vibrations that make the residents feel uncomfortable due to lack of rigidity or resonance with disturbance vibrations. For example, TMD (tuned mass It has been proposed to install dampers (dynamic dampers) on beams and floors. By installing a weight (additional mass) that vibrates in synchronism with the vibration of the beam or the floor, the vibration of the beam or the floor is reduced by greatly vibrating the weight.
Although not intended to prevent floor and beam vertical vibration, Patent Document 2 discloses that horizontal vibration of a seismic isolation object is applied to rotational motion of a rotating mass body (rotating weight) via a transmission mechanism composed of a gear train. There is a disclosure of a seismic isolation device that functions as a TMD utilizing the rotational inertial mass that results from the conversion.
JP-A-10-252253 JP 2007-10110 A

In general TMD as disclosed in Patent Document 1, the mass of a weight necessary for effectively obtaining a vibration reduction effect is usually 1 ton or more, and such a mass with such a large mass is added. This is not preferable because it places a heavy burden on the floor and beams. In addition, since it is often difficult to install large mass weights in terms of securing space, it is common to disperse a plurality of small mass weights. Therefore, there are also problems in terms of workability and economy. There is.
In addition, it is conceivable to apply a seismic isolation device using rotational inertial mass as shown in Patent Document 2 as a vertical vibration damping device, in which case the required mass of the rotating mass body can be reduced, but this conventional Since a seismic isolation device of a kind is provided with a transmission mechanism using a complicated gear train, the entire device is too complicated and inevitably has to be expensive, and has not been widely spread.

  In view of the above circumstances, the present invention provides a vibration damping mechanism for reducing vibrations in various structures, in particular, an effective and appropriate vibration damping mechanism that can effectively reduce vertical vibrations of building floors and beams with a simple mechanism. It is intended to provide.

The present invention is a vibration damping mechanism that is interposed between two structures that vibrate relative to each other in a direction to be separated from each other, and that reduces relative vibration in the direction of separation that occurs between the structures. A rotary inertia mass damper connected to any one of the structures and operating by the relative vibration, and any of the two structures connected in series to the rotary inertia mass damper A spring element connected to the other structure, and the spring element is made of a plate material, the central part of which is connected to the rotary inertia mass damper, and both ends of the plate material The portion is connected to the other structure.
In the present invention, it is preferable that the position of the connection point at both ends of the plate member with respect to the other structure is variable, and the rigidity of the plate member is variable by adjusting the distance between the two connection points. In addition, it is preferable to integrally laminate a viscoelastic body as a damping element on the plate material.

The vibration damping mechanism of the present invention has a small and lightweight rotary inertia mass damper as well as an excellent vibration damping effect obtained by the function of the additional vibration system composed of a rotary inertia mass damper and a plate material as a spring element as TMD. It is a simple configuration in which simple plate materials are simply connected in series and does not require complicated and sophisticated mechanisms. Therefore, it can be manufactured at a sufficiently low cost, and the installation space for the structure to be controlled is also large. It can be installed easily and inexpensively without necessity, and is particularly suitable as a mechanism for reducing vertical vibrations of building floors and beams.
In particular, by adopting a configuration that adjusts the distance between the connection points at both ends of the plate material with respect to the structure, the rigidity of the plate material can be easily adjusted and the tuning for functioning as a TMD can be performed easily and with high accuracy. be able to.
Further, by laminating a viscoelastic body integrally with a plate material as a spring element, the plate material can naturally have vibration damping performance.

  An embodiment of the present invention will be described with reference to FIGS. This embodiment is for reducing the vertical vibration of a building floor as a vibration control target. In FIG. 1, reference numeral 1 denotes a floor on the upper floor as a vibration control target, and 2 denotes a floor on the lower floor (or a beam or beam). The vibration damping mechanism A of this embodiment is installed between the upper and lower floors 1 and 2 so as to function as a TMD (tuned mass damper: dynamic vibration absorber).

  The vibration damping mechanism A of the present embodiment is composed of a known rotary inertia mass damper 3 using a ball screw mechanism and a plate member 4 as a spring element connected in series thereto, in the case of the illustrated example. The rotary inertia mass damper 3 is connected to the upper surface of the lower floor 2 via a support 5 made of pipe material or the like, and the plate 4 is connected to the upper floor 1 via a spacer 6 made of channel steel or the like. Connected to the bottom surface.

  The rotary inertia mass damper 3 according to the present embodiment has a ball screw 8 whose one end (lower end in the illustrated example) is rotatably supported by a receiver 7, a ball nut 9 screwed to the ball screw 8, and a ball screw 8. The flywheel 10 is fixed to the other end (upper end in the illustrated example). When the ball nut 9 moves up and down with respect to the ball screw 8, the ball screw 8 is rotated (rotated) and fixed thereto. The flywheel 10 is rotated together with the ball screw 8, and the rotational inertial mass generated thereby is used as a damping force.

The plate material 4 in the present embodiment functions a steel plate or the like having a predetermined rigidity as a plate spring, and a central portion thereof is sandwiched between the ball nut 9 and the jig plate 11 with respect to the ball nut 9. (That is, to the rotary inertia mass damper 3) by bolt fastening, and both ends of the plate member 4 are connected to the lower portion of the spacer 6 in a form sandwiched by the upper and lower thick plates 12.
In addition, highly rigid channel steel is used as the spacer 6 in this embodiment, the reinforcement rib 13 is welded to the important point, The upper flange of the channel steel is on the floor 1 of the upper floor. On the other hand, it is fixed by an anchor, and both end portions of the plate member 4 are connected to the lower flange via the thick plate 12 by bolt fastening.

In the vibration damping mechanism A configured as described above, when a relative vibration in the vertical direction occurs between the upper and lower floors 1 and 2, the relative vibration is transmitted to the rotary inertia mass damper 3 via the plate member 4 to rotate the rotary inertia. The mass damper 3 is activated. That is, the plate member 4 connected to the upper floor 1 via the spacer 6 moves up and down relatively with respect to the lower floor 2 so that the ball nut 9 connected to the plate 4 is moved. The ball screw 8 moves up and down relatively with respect to the ball screw 8, and the ball screw 8 is rotated (spinned), so that the flywheel 10 rotates to generate a large rotational inertial mass.
Therefore, by synchronizing the natural frequency of the additional vibration system composed of the rotary inertia mass damper 3 and the plate material 4 constituting the vibration damping mechanism A with the natural frequency (or the control target frequency) of the floor 1, Since the damping mechanism A functions as a TMD and the rotational inertial mass generated by the flywheel 10 is much larger than the actual mass of the flywheel 10, even if the flywheel 10 is small and lightweight, A damping effect equivalent to or higher than that of ordinary TMD with a large mass weight can be obtained.

FIG. 2 shows a theoretical model of the vibration damping mechanism of the present embodiment, and FIG. 3 shows an analysis result of the vibration damping effect when each specification is set as follows based on this model.
The effective mass M of the upper floor 1 to be controlled is 50t, the stiffness K of the structure composed of the upper and lower floors 1 and 2 is 50tf / cm, its primary natural frequency 5Hz (primary natural angular frequency ω ₀ = 31.4 rad / sec). Note that ω ₀ ² = K / M.
When PL36-97φ is used as the flywheel 10 and its mass is set to 2 kg, when the rotational inertia is Ir = 25.3 kgcm ² and the lead of the ball screw 8 is L = 1 cm, the apparent inertia mass in the vertical direction is m = 25.3. × 4π ² = 1t, so the mass ratio is m / M = 0.02.
The rigidity k of the plate member 4 in the damping mechanism A is 1 tf / cm, and therefore the rigidity ratio k / K = 0.02. The damping coefficient of the dashpot as the damping element 14 is set to c = 5.8 kgf / kine, and the damper damping h = c / (2 mω ₀ ) = 0.09.
In this case, the analysis result shown in FIG. 3 indicates that the response magnification at the primary natural angular frequency ω ₀ is 50 times in the absence of the vibration damping mechanism A, whereas the vibration damping mechanism A By installing, the response magnification can be drastically reduced to 10 times or less (reduction rate 84%).

  As described above, the vibration damping mechanism according to the present embodiment has an extremely simple structure including the small and light rotary inertia mass damper 3 having the flywheel 10 of only about 2 kg and the simple plate material 4, but has excellent damping performance. Since it does not use a complicated transmission mechanism as shown in Patent Document 2 as well as being able to obtain a vibration effect, it can be manufactured at a sufficiently low cost, and is simply a pipe material for the upper and lower floors 1 and 2. Since it is only necessary to install the support 5 made of the like and the spacer 6 made of simple grooved steel etc., the work for installing it can be easily performed without any trouble, and no installation space is required. .

In order for the vibration damping mechanism A of the present embodiment to function as TMD, it is necessary to synchronize its natural frequency with the natural frequency (or frequency to be controlled) of the floor 1, and for this purpose, the material of the plate material 4 The rigidity k needs to be set appropriately by adjusting the thickness, but the rigidity k of the plate member 4 can be set only by changing the position of the connection point with respect to the floor 1.
That is, when the plate member 4 is connected to the floor 1 via the spacer 6 as in the above embodiment, the connection points at both ends of the plate member 4 with respect to the lower portion of the spacer 6 are sandwiched by the thick plate 12 and between the two connection points. The thickness k of the plate is also adjusted by moving the thick plates 12 on both sides in the direction of separating and contacting each other (the length direction of the plate 4) and adjusting the distance between the two connection points. (Naturally, the rigidity k decreases as the distance between the two connection points increases, and the rigidity k increases as the distance between the two connection points decreases).
Therefore, the troublesome adjustment of setting the material and the plate thickness of the plate material 4 each time is not necessary, and the rigidity thereof is obtained only by an extremely simple and simple operation of simply adjusting the position of the connection point of the plate material 4 with respect to the spacer 6. k can be set optimally, and therefore, the tuning operation as TMD can be easily performed with high accuracy, and can be easily changed or reset as required.

Further, by incorporating an appropriate damping element 14 (corresponding to the dashpot in FIG. 2) into the plate member 4, vibration of the plate member 4 itself can be effectively damped. As a configuration example in that case, as shown in FIG. 1, a viscoelastic body as a damping element 14 is integrally laminated on the plate member 4 and is sandwiched between the plate member 4 and the mounting plate 15. It is possible. According to this, the vertical vibration of the plate member 4 is effectively damped by the viscoelastic deformation of the viscoelastic body, and it is not necessary to secure a special space for installing the damping element.
In addition, also by using a damping steel plate as a raw material of the plate member 4, the plate member 4 itself has a damping function, and the same vibration damping effect can be obtained.

As mentioned above, although one Embodiment of this invention was described, the said embodiment is only a suitable example to the last, and this invention is not limited to the said embodiment.
For example, in the above-described embodiment, the rotary inertia mass damper 3 is connected to the lower floor 2 and the plate member 4 is connected to the upper floor 1. The same applies when 3 is connected to the upper floor 1 and the plate 4 is connected to the lower floor.
In addition, the present invention is optimally installed for the purpose of reducing the vertical vibration of a building floor or beam as in the above embodiment, but is not limited thereto, and various structures and structures are not limited thereto. It can be widely applied for the purpose of reducing vibrations in various directions of the body. For example, if the vibration damping mechanism of the above embodiment is placed sideways as it is and installed between the walls on both sides, it is possible to reduce the horizontal relative vibrations of these walls. It is also possible to apply the vibration damping mechanism of the present invention as a seismic isolation device, and to support the entire upper structure against seismic motion in horizontal and vertical directions.

Further, the vibration damping mechanism of the present invention may be installed so that the rotary inertia mass damper 3 and the plate material 4 are connected in series so as to function as a TMD. It can be changed.
For example, the rotary inertia mass damper 3 is preferably a ball screw mechanism as in the above embodiment, but is not limited thereto, and may be of an appropriate type as long as a desired rotary inertia mass effect can be obtained. Can be arbitrarily adopted. Further, the rotary inertia mass damper 3 is not limited to being installed via the support 5 as in the above-described embodiment. For example, the support 3 may be omitted and the rotary inertia mass damper 3 may be directly connected to the structure. It is done.
The plate material 4 may also be any material that functions as a leaf spring having a desired rigidity in order to cause the entire damping mechanism A to function as TMD. The shape and material of the plate material 4 are arbitrary as long as the plate material 4 is used. Needless to say, the specific configuration of the details thereof can be variously changed as long as the central portion and the both end portions thereof are connected to the rotary inertia mass damper 3 and the structure, respectively. For example, in the above-described embodiment, both ends of the plate member 4 are connected to the structure through the grooved steel as the spacer 6, but the member as the spacer 6 and the shape thereof are grooved as long as they have a desired rigidity. It is not limited to steel, and it is optional. In some cases, the spacer 6 may be omitted and the plate 4 itself may be directly connected to the structure. It is also conceivable to add various mechanisms to make the rigidity of the plate member 4 variable.

It is a schematic block diagram of the damping mechanism which is embodiment of this invention. This is the principle model. It is a figure which shows the analysis result about a damping effect similarly.

Explanation of symbols

A Damping mechanism 1, 2 Floor (structure)
3 Rotating inertia mass damper 4 Plate material (spring element)
5 Support 6 Spacer 7 Receiving Tool 8 Ball Screw 9 Ball Nut 10 Flywheel 11 Jig Plate 12 Thick Plate 13 Reinforcement Rib 14 Attenuation Element 15 Mounting Plate

Claims (3)

A vibration damping mechanism that is interposed between two structures that vibrate relative to each other in a direction to be separated from each other, and that reduces relative vibration in the direction of separation between the structures,
A rotary inertia mass damper connected to one of the two structures and operated by the relative vibration, and the two structures connected in series to the rotary inertia mass damper A spring element connected to one of the other structures,
The spring element is made of a plate material, and a central portion thereof is connected to the rotary inertia mass damper, and both end portions of the plate material are connected to the other structure. Damping mechanism. The vibration damping mechanism according to claim 1,
The position of the connection point at both ends of the plate member with respect to the other structure is variable, and the rigidity of the plate member is variable by adjusting the distance between the two connection points. . The vibration damping mechanism according to claim 1 or 2,
A vibration damping mechanism, wherein a viscoelastic body as a damping element is integrally laminated on the plate material.

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