Vibration damping system

Abstract

We provide a vibration damping system that can achieve high vibration damping effectiveness while reducing the installation space required. [Solution] The building 11 comprises a cable material 2 that connects the top 11a and the base 11b of the building 11 and into which tension is introduced; an inertia mass damper 3 provided on the top 11a or the base 11b of the building 11; and a displacement direction conversion amplification mechanism 4 that converts the displacement of the cable material 2 into a displacement in the direction of action of the inertia mass damper 3, amplifies it, and inputs it to the inertia mass damper 3.

Description

Technical Field

[0001] The present invention relates to a vibration damping system.

Background Art

[0002] Due to the frequent occurrence of large earthquakes in recent years, the required performance regarding the seismic resistance of structures (buildings) has been increasing. In addition, in the Noto Peninsula earthquake in 2024, the collapse of structures accompanied by the pulling out of pile foundations was also observed. On the other hand, among existing super high-rise buildings, condominiums, high-rise buildings with a narrow frontage and a large tower ratio standing in urban areas, and even traditional wooden buildings such as temples and shrines, many cannot be said to have sufficient seismic resistance against large earthquakes beyond expectations. Particularly, in structures with a large tower ratio, regardless of whether they are of S structure or RC structure, bending deformation is more prominent than shear deformation. Therefore, even if an interlayer installation type damper acting on interlayer shear deformation is provided, there is a problem that the effect is reduced.

[0003] In order to address such problems, in recent years, a seismic countermeasure TMD equipped with a several-hundred-ton weight may be installed at the top of a structure (see, for example, Patent Document 1). However, when adopting a TMD, a vast space for installing a several-hundred-ton weight on the rooftop floor of the structure or the like must be secured. In the case of existing structures, there is also a problem that the column beams must be reinforced to support the several-hundred-ton weight.

[0004] In order to address such problems, a method of directly connecting the rooftop of a structure and the ground with a damper for vibration damping has been proposed. However, unless the support member for supporting the damper is made rigid, only the support member will deform and the deformation will not be transmitted to the damper. For this reason, Patent Document 2 discloses a technique for damping the bending deformation of a structure by connecting the top and the base of the structure with a rotational inertia mass damper acting in the vertical direction and synchronizing them. In addition, Patent Document 3 discloses a technique for omitting a buckling prevention mechanism by introducing tension into the support member of a damper.

Prior Art Documents

[0005] [Patent Document 1] Patent No. 6694672 [Patent Document 2] Patent No. 5399540 [Patent Document 3] Japanese Patent Publication No. 2023-67759 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, these technologies have the problem that they are ineffective unless dampers are installed at various points, such as the outer perimeter of structures that undergo significant vertical deformation due to bending, requiring ample space to install dampers and other devices.

[0007] Therefore, the present invention aims to provide a vibration damping system that can achieve a high vibration damping effect while reducing the installation space required. [Means for solving the problem]

[0008] To achieve the above objective, the vibration damping system according to the present invention comprises a tension member connecting the upper and lower parts of a structure, an inertia mass damper provided on the upper or lower part of the structure, and a displacement direction conversion amplification mechanism that converts the displacement of the tension member into a displacement in the direction of action of the inertia mass damper, amplifies it, and inputs it to the inertia mass damper.

[0009] In this invention, the horizontal deformation of a structure acting on a tension member can be converted into a displacement in the direction of action of an inertial mass damper by a displacement direction conversion and amplification mechanism, and amplified before being input to the inertial mass damper. Therefore, in this invention, the deformation of the inertial mass damper can be amplified, increasing the energy absorption efficiency and achieving a high vibration damping effect. Furthermore, even for significant bending deformations in super high-rise buildings and tower-like buildings, which were difficult to address with conventional dampers installed between floors, a high vibration damping effect can be expected, and the overturning moment can also be greatly reduced. In this invention, the number of dampers can be reduced compared to when dampers are installed between each floor of a structure, and the installation space for dampers can be reduced. In addition, the cost of damper management can be greatly reduced.

[0010] In the vibration damping system according to the present invention, the angle between the axial direction of the tension member and the direction of action of the inertial mass damper may be set to be greater than 45° and less than or equal to 90°.

[0011] With this configuration, in response to the horizontal deformation of the upper part of the structure caused by shear deformation, a deformation corresponding to the angle between the axial direction of the tension member and the direction of action of the inertial mass damper acts on the inertial mass damper via the tension member and the displacement direction conversion amplification mechanism. In other words, it can be effective not only against the bending deformation of the structure but also against the more dominant shear deformation.

[0012] In the vibration damping system according to the present invention, the displacement direction conversion amplification mechanism may be a lever mechanism connecting the tension member and the inertial mass damper.

[0013] In the vibration damping system according to the present invention, the displacement direction conversion amplification mechanism may be a toggle mechanism connecting the tension member and the inertial mass damper.

[0014] With this configuration, the displacement direction conversion amplification mechanism can convert the horizontal deformation of the structure acting on the tension member into a displacement in the direction of action of the inertial mass damper, and amplify it before inputting it to the inertial mass damper. The displacement direction conversion amplification mechanism can be made into a simple structure.

[0015] In the vibration damping system according to the present invention, a plurality of tension members are provided at positions symmetrical with respect to the rigid center of the structure, and each of the plurality of tension members may be provided with the displacement direction conversion amplification mechanism.

[0016] This configuration prevents the structure from tilting and deforming in one direction due to the tension introduced into the tension members.

[0017] In the vibration damping system according to the present invention, two tension members are provided at positions symmetrical with respect to the rigid center of the structure, and the end of each of the two tension members connected to the displacement direction conversion amplification mechanism is changed by the displacement direction conversion amplification mechanism to a position extending in the direction of action of the inertial mass damper, and they are connected to each other via a movable body that can move in the direction of action of the inertial mass damper, and the inertial mass damper may be connected to the movable body.

[0018] This configuration ensures that the two tension members, positioned symmetrically with respect to the rigid center of the structure, are always under tension, thereby reducing the tension required to apply to them.

[0019] The vibration damping system according to the present invention may include a spring element connected in series with the inertial mass damper.

[0020] This configuration makes it easy to adjust the period of the inertia mass damper by adjusting the specifications of the spring element.

[0021] In the vibration damping system according to the present invention, a plurality of inertial mass dampers are provided, and one of the plurality of inertial mass dampers may be set to tune to one natural vibration mode of the structure, while the other inertial mass dampers may be set to tune to other natural vibration modes of the structure.

[0022] By adopting such a configuration, the vibration of the structure can be reduced for each of the plurality of natural vibration modes.

Advantages of the Invention

[0023] According to the present invention, a high vibration damping effect can be achieved, and the installation space can be reduced.

Brief Description of the Drawings

[0024] [Figure 1] It is a model diagram of a mass point system of the vibration damping system according to the first embodiment. [Figure 2] It is a diagram for explaining the amplification factor of the strut mechanism. [Figure 3] It is a plan view of the vibration damping system. [Figure 4] It is a sectional view taken along line A-A of FIG. 3. [Figure 5] It is a sectional view showing the vibration damping system during an earthquake. [Figure 6] It is a sectional view showing a vibration damping system in which cable materials are arranged in a crossed manner. [Figure 7] It is a model diagram of a mass point system of the vibration damping system according to the second embodiment. [Figure 8] It is a sectional view of the vibration damping system according to the second embodiment. [Figure 9] It is a sectional view showing a vibration damping system in which an inertial mass damper and a displacement direction conversion and amplification mechanism are provided at the top of a building. [Figure 10] It is a sectional view showing a vibration damping system in which a pulley is adopted in the displacement direction conversion and amplification mechanism. [Figure 11] It is a model diagram of a mass point system of the vibration damping system according to the third embodiment. [Figure 12] It is a plan view of the vibration damping system. [Figure 13] It is a sectional view taken along line B-B of FIG. 12. [Figure 14] It is a sectional view showing the vibration damping system during an earthquake. [Figure 15] It is a model diagram of a mass point system of the vibration damping system according to a modification of the third embodiment. [Figure 16]This is a model diagram of a mass system of a vibration damping system according to another modification of the third embodiment. [Figure 17] Figure 16 is a model diagram of the vibration control system as viewed from the X direction, showing a system of point masses. [Figure 18] This is a table showing the specifications of the building's analytical model. [Figure 19] This figure shows the analysis model for Type 1 (lever mechanism type). [Figure 20] This graph shows the maximum absolute acceleration of Type 1 (lever mechanism type). [Figure 21] This graph shows the maximum layer displacement for Type 1 (lever mechanism type). [Figure 22] This graph shows the maximum tipping moment for Type 1 (lever mechanism type). [Figure 23] This graph shows the transfer function between the ground motion input and the absolute acceleration response at the 5th layer for Type 1 (lever mechanism type). [Figure 24] This figure shows the analysis model for Type 2 (lever mechanism type with simultaneous primary and secondary tuning). [Figure 25] This graph shows the maximum absolute acceleration of Type 2 (lever mechanism type with simultaneous primary and secondary tuning). [Figure 26] This graph shows the maximum layer displacement for Type 2 (lever mechanism type with simultaneous primary and secondary tuning). [Figure 27] This graph shows the maximum overturning moment for Type 2 (lever mechanism type with simultaneous primary and secondary synchronization). [Figure 28] This graph shows the transfer function between the ground motion input and the absolute acceleration response at the fifth layer for Type 2 (lever mechanism type with simultaneous primary and secondary tuning). [Figure 29] This figure shows a Type 3 (toggle type) analysis model. [Figure 30] This figure shows a magnified view of the base of the analysis model. [Figure 31] This graph shows the analysis results of the maximum inter-story drift angle response for Type 3 (toggle type). [Figure 32] This diagram shows a vibration control system with cables installed around the perimeter of a building. [Figure 33] This is a model diagram of a mass system in a vibration damping system equipped with a relief mechanism in an inertial mass damper. [Modes for carrying out the invention]

[0025] (First Embodiment) The vibration damping system according to the first embodiment of the present invention will be described below with reference to Figures 1-6. The vibration control system 1 according to the first embodiment is installed in a building 11, which is the structure to be controlled. The building 11 is, for example, a high-rise building or a super high-rise building. The building 11 is supported by the ground. In Figure 1, the building 11 and the vibration control system 1 are shown as a system of mass points. The building 11 corresponds to the structure in the claims.

[0026] The vibration damping system 1 of the first embodiment includes a cable material 2, an inertia mass damper 3, and a displacement direction conversion amplification mechanism 4. The inertia mass damper 3 and the displacement direction conversion amplification mechanism 4 are provided on the base 11b of the building 11. The inertia mass damper 3 is provided on the base 11b of the building 11 so as to act on a horizontal displacement. The direction of action of the inertia mass damper 3 is denoted as the X direction. The inertia mass damper 3 acts on the displacement (swaying) of the building 11 in the X direction. The horizontal direction perpendicular to the X direction is denoted as the Y direction. The displacement direction conversion amplification mechanism 4 is provided between the cable material 2 and the inertia mass damper 3. The displacement direction conversion amplification mechanism 4 converts the displacement direction of the cable material 2 to the direction of action of the inertia mass damper 3, amplifies the displacement of the cable material 2, and inputs it to the inertia mass damper 3.

[0027] Cable material 2 is a tension member. Tension is introduced into cable material 2 in advance. Cable material 2 is a wire that spans from near the top 11a to near the base 11b of building 11. Cable material 2 is, for example, several tens or several hundred meters long. Cable material 2 is, for example, a PC steel strand used as a structural cable in bridges or buildings. One end 2a of cable material 2 is joined to the top 11a of building 11. The other end 2b of cable material 2 is joined to a displacement direction conversion amplification mechanism 4 provided at the base 11b of building 11. The joint between one end 2a of cable material 2 and the top 11a of building 11, and the joint between the other end 2b of cable material 2 and the displacement direction conversion amplification mechanism 4 are both rotatable pin joints that do not transmit bending stress. The pin joint is, for example, made by a clevis. Cable material 2 may be provided with adjusters such as turnbuckles for introducing tension. Instead of cable material 2, a tension rod or the like may be provided as a tensioning member.

[0028] The cable members 2 are installed around the perimeter of the building 11 and in the atrium 13 located in the center of the building 11, extending vertically throughout. Multiple cable members 2 are arranged in positions that are approximately symmetrical (line symmetry or point symmetry) with respect to the rigid center of the building 11. This prevents the building 11 from deforming (tilting) in one direction due to the tension introduced into the cable members 2. In this embodiment, two cable members 2 are arranged symmetrically with respect to the rigid center of the building 11 in a vertical plane along the X direction. The two cable members 2 each extend in a direction along the vertical plane in the X direction. The angle θ between the axial direction of the cable member 2 and the direction of action of the inertial mass damper 3 (the direction in which the building 11 sways, the X direction) is 45° < θ ≤ 90°.

[0029] The tension initially introduced into the cable material 2 is set to a value such that no compressive force acts due to the reaction force of the inertial mass damper 3. In this way, even if the cable material 2 is thin, i.e., has a small cross-sectional shape, buckling due to the compressive force from the reaction force of the inertial mass damper 3 can be prevented, thus eliminating the need for a buckling stiffener in the cable material 2.

[0030] The two cable members 2 are each connected to separate displacement direction conversion amplification mechanisms 4. The displacement direction conversion amplification mechanism 4 to which one of the two cable members 2 is connected and the displacement direction conversion amplification mechanism 4 to which the other cable member 2 is connected are arranged symmetrically with respect to the rigid center of the building 11 when viewed from the Y direction. The displacement direction conversion amplification mechanism 4 is a lever mechanism that connects the cable members 2 and the inertial mass damper 3.

[0031] The displacement direction conversion amplification mechanism 4 has a first connecting piece 41 and a second connecting piece 42 joined to each other. The first connecting piece 41 and the second connecting piece 42 are each rod-shaped. One end 411 in the axial direction of the first connecting piece 41 and one end 421 in the axial direction of the second connecting piece 42 are joined. The axes of the first connecting piece 41 and the axes of the second connecting piece 42 are each located in a vertical plane along the X direction. Note that the first connecting piece 41 and the second connecting piece 42 may have shapes other than rods.

[0032] The other axial end 412 of the first connecting piece 41 is connected to the other end 2b of the cable material 2. It is desirable that the first connecting piece 41 and the cable material 2 are connected such that the angle θ1 (see Figure 2) between their respective axes is approximately 90°. The other end 422 of the second connecting piece 42 is connected to the inertia mass damper 3 via a horizontal spring 5 for period adjustment. The horizontal spring 5 extends in the direction in which the inertia mass damper 3 acts, i.e., in the X direction. It is desirable that the second connecting piece 42 and the horizontal spring 5 are connected such that the angle θ2 (see Figure 2) between their respective axes is approximately 90°.

[0033] The displacement direction conversion amplifier mechanism 4 has a connection point 43 between the first connecting piece 41 and the second connecting piece 42 that is rotatably mounted on a shaft portion 44 supported by the building 11. The axial direction of this shaft portion 44 is the Y direction. When the building 11 is displaced and the displacement of the cable material 2 is transmitted to the first connecting piece 41, the displacement direction conversion amplifier mechanism 4 rotates around the axis of the shaft portion 44, causing the second connecting piece 42 to also be displaced. As a result, the displacement of the second connecting piece 42 in the X direction is transmitted to the inertia mass damper 3 via the horizontal spring 5.

[0034] As shown in Figure 2, if the axial length dimension of the first connecting piece 41 is denoted as a and the axial length dimension of the second connecting piece 42 is denoted as b, the amplification factor β of the displacement amount of the second connecting piece 42 (inertia mass damper 3) with respect to the displacement amount of the first connecting piece 41 (cable material 2) in the lever mechanism of the displacement direction conversion amplification mechanism 4 is given by the following equation. Amplification factor β = b / a By increasing the axial length dimension b of the second connecting piece 42 relative to the axial length dimension a of the first connecting piece 41, the deformation acting on the inertia mass damper 3 can be increased even when the angle θ between the axial direction of the cable material 2 and the direction of action of the inertia mass damper 3 is acute.

[0035] As described above, the angle θ between the axial direction of the cable material 2 and the direction of action (X direction) of the inertia mass damper 3 is 45° < θ ≤ 90°. As a result, in response to the horizontal deformation of the top 11a of the building 11 due to the shear deformation of the building 11, a deformation corresponding to the angle θ acts on the inertia mass damper 3 via the cable material 2 and the displacement direction conversion amplification mechanism 4. In other words, it is effective not only against the bending deformation of the building 11 but also against the more dominant shear deformation. For this reason, the cable material 2 may be provided on both the outer perimeter of the building 11 and the atrium 13. The smaller the angle θ, the more effective it is against the shear deformation of the building 11.

[0036] The inertia mass damper 3 is a device that utilizes a ball screw, such as a Dynamic Screw (registered trademark). In this embodiment, the inertia mass damper 3 is connected in parallel with a viscous damping element 36, and a spring element 37 is connected in series to the inertia mass damper 3 and the viscous damping element 36, which are arranged in parallel. With this configuration, the period of the inertia mass damper 3 can be easily adjusted by adjusting the specifications of the viscous damping element 36 and the spring element 37. The spring element 37 is, for example, a coil spring, a disc spring, or rubber.

[0037] Figures 3 and 4 show the state in which a vibration damping system 1 is installed in a building 11 having an atrium 13 extending throughout the entire vertical space inside. Two vibration damping systems 1 are installed in the atrium 13, spaced apart in the Y direction. The two vibration damping systems 1 have the same configuration. The upper ends (one end 2a) of each of the two cable members 2 of the vibration damping system 1 are connected to the upper end 14a (top 11a of the building 11) of the inner perimeter wall 14 of the building 11 facing the atrium 13. The lower ends (the other end 2b) of each of the two cable members 2 are connected to a displacement direction conversion amplification mechanism 4 provided on the floor 131 (base 11b of the building 11) of the atrium 13.

[0038] One of the two cable members 2 is connected to a displacement direction conversion amplification mechanism 4, and the other cable member 2 is connected to another displacement direction conversion amplification mechanism 4, both of which are connected to an inertia mass damper 3 via a connecting block 6 supported by a roller 61 that is movable in the X direction. The roller 61 is, for example, a rolling bearing such as a linear guide. The connecting block 6 is a jig for connecting the cable material 2 with the inertia mass damper 3 and the roller 61. The connecting block 6 may be made of steel or other materials to ensure manufacturing accuracy. The material used to manufacture the connecting block 6 may be set as appropriate. Although the connecting block 6 is shown as a rectangular block in the drawing, it may be in any shape other than the above, as long as it can connect the cable material 2 with the inertia mass damper 3 and the roller 61.

[0039] Figure 5 shows the state of the vibration control system 1 when the building 11 deforms in the X direction due to an earthquake. The displacement of the two cable members 2 is transmitted to the displacement direction conversion amplification mechanism 4, where the direction of the displacement is converted to the X direction and the amount of displacement is amplified. This is then transmitted to the inertia mass damper 3 via the connecting block 6 and damped by the action of the inertia mass damper 3.

[0040] As shown in Figure 6, the two cable members 2 may be arranged so as to intersect when viewed from the Y direction. In the vibration damping system 1 shown in Figure 6, the upper end (one end 2a) of one of the two cable members 2 is positioned to one side in the X direction relative to the upper end (one end 2a) of the other cable member 2, and the lower end (the other end 2b) of one cable member 2 is positioned to the other side in the X direction relative to the lower end (the other end 2b) of the other cable member 2. Inertial mass dampers 3 are provided on both sides of the connecting block 6, and one cable member 2 may be connected to one inertial mass damper 3 via a displacement direction conversion amplification mechanism 4, and the other cable member 2 may be connected to the other inertial mass damper 3 via a displacement direction conversion amplification mechanism 4.

[0041] Next, the operation and effects of the vibration damping system 1 according to the first embodiment will be described. In the vibration control system 1 according to the first embodiment, a cable 2 connecting the top 11a and base 11b of the building 11 is connected to an inertia mass damper 3 via a displacement direction conversion amplification mechanism 4. This allows the horizontal deformation of the building 11 acting on the cable 2 to be converted and amplified by the displacement direction conversion amplification mechanism 4 into a displacement in the direction of action (X direction) of the inertia mass damper 3, and then input to the inertia mass damper 3. Therefore, in the vibration control system 1 according to this embodiment, the deformation of the inertia mass damper 3 can be amplified, increasing the energy absorption efficiency and achieving a high vibration control effect. Furthermore, a high vibration control effect can be expected even against significant bending deformation in skyscrapers and tower-like buildings, which were difficult to address with conventional inter-story dampers, and the overturning moment can also be significantly reduced. In the vibration control system 1 according to this embodiment, the number of dampers can be reduced compared to the case where dampers are installed between each floor of the building 11, thus reducing the installation space for the dampers. In addition, the costs associated with damper management can be significantly reduced. When the vibration control system 1 according to this embodiment is adopted in vibration control renovation of an existing building, the scope of work is limited to only the top 11a and base 11b of the building 11, compared to when dampers are installed between floors, thus enabling a reduction in construction time and costs. When the cable material 2 is connected in a straight line like a brace material, the cable material 2 only rotates and hardly deforms in the axial direction. However, by being connected to the displacement direction conversion amplification mechanism 4, the deformation in the axial direction can be input to the inertial mass damper 3. In the vibration damping system 1 according to this embodiment, the axial stiffness required for the cable material 2 can be reduced by utilizing the synchronization effect of the inertial mass damper 3, thereby minimizing the cross-section of the cable material 2 and improving cost-effectiveness.

[0042] In the vibration control system 1 according to this embodiment, a lever mechanism is employed in the displacement direction conversion amplification mechanism 4. This allows the displacement direction conversion amplification mechanism 4 to convert the horizontal deformation of the building 11 acting on the cable material 2 into a displacement in the direction of action of the inertial mass damper 3, and to amplify it before inputting it to the inertial mass damper 3. The displacement direction conversion amplification mechanism 4 can be made into a simple structure.

[0043] In the vibration damping system 1 according to this embodiment, an inertial mass damper 3 is employed, and the amount of movement (displacement) of the cable material 2 input to the inertial mass damper 3 is amplified by the displacement direction conversion amplification mechanism 4. In addition, the inertial mass damper 3, such as a dynamic screw (registered trademark), can also amplify the actual mass of the weight as rotational inertia mass by several thousand times (approximately 4500 to 7000 times) using a ball screw. As a result, the mass of the weight of the inertial mass damper 3 required to obtain the same damping as the additional mass body of a conventional vibration damping system that amplified the inertial force of the additional mass body to dampen vibrations can be reduced. The influence of the weight of the inertial mass damper 3 on the building 11 can be reduced.

[0044] The two cable members 2 are arranged symmetrically with respect to the rigid center of the building 11 when viewed from the Y direction. The displacement direction conversion amplifier mechanism 4 to which one of the two cable members 2 is connected and the displacement direction conversion amplifier mechanism 4 to which the other cable member 2 is connected are also arranged symmetrically with respect to the rigid center of the building 11 when viewed from the Y direction. With this configuration, the two cable members 2 are always under tension, so the tension introduced into the cable members 2 can be reduced.

[0045] Next, other embodiments will be described. The same reference numerals will be used for components and parts identical or similar to those in the first embodiment described above, and their descriptions will be omitted. Configurations different from the first embodiment will be described. (Second Embodiment) As shown in Figures 7 and 8, the vibration damping system 1B according to the second embodiment is provided with inertia mass dampers 3 on both sides of the connecting block 6 in the X direction. In the second embodiment as well, the vibration damping system 1B is provided in the atrium 13 of the building 11. An inertial mass damper 3 provided on one side of the connecting block 6 in the X direction will be referred to as the first inertial mass damper 31, and an inertial mass damper 3 provided on the other side of the connecting block 6 in the X direction will be referred to as the second inertial mass damper 32. The first inertial mass damper 31 and the second inertial mass damper 32 are provided on the same straight line or parallel to each other. The first inertial mass damper 31 is tuned to the first natural vibration mode of the building 11, and the second inertial mass damper 32 is tuned to the second natural vibration mode of the building 11.

[0046] As shown in Figure 9, the vibration control system 1B may be configured by reversing the vertical arrangement, with the first inertial mass damper 31, second inertial mass damper 32, displacement direction conversion amplification mechanism 4, and connecting block 6 positioned at the top 11a of the building 11. The cable material 2 is arranged in a cross pattern. The lower end (one end 2a) of the cable material 2 is connected to the base 11b of the building 11. The upper end (the other end 2b) of the cable material 2 is connected to the displacement direction conversion amplification mechanism 4 provided at the top 11a of the building 11. By positioning the first inertial mass damper 31, second inertial mass damper 32, displacement direction conversion amplification mechanism 4, and connecting block 6 at the top 11a of the building 11, the base 11b of the building 11 can be utilized for purposes other than the vibration control system 1B.

[0047] As shown in Figure 10, the vibration control system 1B may have a pulley as the displacement direction conversion amplification mechanism 4B provided at the top 11a of the building 11, with the upper ends of two cable members 2, positioned symmetrically with respect to the rigid center of the building 11, being hung on the pulley of the displacement direction conversion amplification mechanism 4B, bent to extend in the X direction, and connected to the connecting block 6. With this configuration, the two cable members 2 are always under tension, thus reducing the tension introduced into the cable members 2. By using a pulley for the displacement direction conversion amplification mechanism 4B, the cable member 2 connecting the connecting block 6 and the base 11b of the building 11 can be made from a single continuous member, resulting in an even simpler configuration compared to the case where a lever mechanism is used for the displacement direction conversion amplification mechanism, as it does not require mechanical members.

[0048] In the vibration control system 1B according to the second embodiment, the vibration of the building 11 can be reduced for both the first and second natural vibration modes. The natural vibration modes to which the first inertial mass damper 31 and the second inertial mass damper 32 are synchronized may be other than the first and second. For example, the first inertial mass damper 31 may be set to synchronize with the third natural vibration mode of the building 11, and the second inertial mass damper 32 may be set to synchronize with the fourth natural vibration mode of the building 11, thereby reducing the vibration of the building 11 for both the third and fourth natural vibration modes. Thus, multiple inertial mass dampers may be provided, with one of the multiple inertial mass dampers set to tune to one natural vibration mode of the structure, and the other inertial mass dampers set to tune to other natural vibration modes of the structure.

[0049] (Third embodiment) As shown in Figure 11, the vibration damping system 1C according to the third embodiment employs a toggle mechanism instead of a lever mechanism in the displacement direction conversion amplification mechanism 4C. As shown in Figures 12 and 13, the vibration damping system 1C is also provided in the atrium 13 of the building 11 in the third embodiment. The vibration damping system 1C according to the third embodiment reduces displacement in the Y direction. The inertia mass damper 3 and the displacement direction conversion amplification mechanism 4 are provided on one side in the Y direction at the bottom of the atrium 13. The inertia mass damper 3 is provided in parallel with a tension introduction spring 8 for introducing tension into the cable material 2. One inertia mass damper 3 is provided for each of the two displacement direction conversion amplification mechanisms 4. The inertia mass damper 3 and tension introduction spring 8, provided in parallel, have one end in the axial direction rotatably connected to the bottom of the atrium 13. The other axial end of the parallel-mounted inertial mass damper 3 and tension introduction spring 8 is positioned above the other end and on the other side in the Y direction, and is connected to the displacement direction conversion amplification mechanism 4. The other end 2b of the cable material 2 is connected to the displacement direction conversion amplification mechanism 4.

[0050] When a toggle mechanism is used as the displacement direction conversion amplification mechanism 4, the orientation of the toggle mechanism is rotated 90° relative to its conventional orientation. By doing so, the action vector of the toggle mechanism becomes ideally oriented, and deformation can be amplified even when the lengths of the two links are extremely different. Furthermore, when a toggle mechanism is used as the displacement direction conversion amplification mechanism 4, deformation in the orthogonal direction can also be easily followed.

[0051] Figure 14 shows the deformation caused by the earthquake. The displacement of the two cable members 2 is transmitted to the displacement direction conversion amplification mechanism 4, where the direction of the displacement is converted to the Y direction and the amount of displacement is amplified, then transmitted to the inertia mass damper 3, where it is damped by the action of the inertia mass damper 3.

[0052] Another form of the vibration control system 1C, which is equipped with a toggle mechanism in the displacement direction conversion amplification mechanism 4, will be described. As shown in the vibration control system 1C in Figure 15, one inertial mass damper 3 may be provided for each of the two displacement direction conversion amplification mechanisms 4, and the system may be configured to receive displacement input from the two displacement direction conversion amplification mechanisms 4. As shown in Figures 16 and 17, the cable material 2 may be arranged in all four directions around the rigid center of the building 11 to form a vibration damping system 1C that acts in the X and Y directions.

[0053] In the vibration damping system 1C according to the third embodiment, a toggle mechanism is employed in the displacement direction conversion amplification mechanism 4, which makes it easy to convert the deformation of the cable material 2 into the direction of action of the inertial mass damper 3, and also allows the deformation of the cable material 2 to be amplified and input to the inertial mass damper 3. The displacement direction conversion amplification mechanism 4 can be made into a simple structure.

[0054] The following shows the results of the analysis and study of buildings to which the vibration control system 1 of the first to third embodiments is applied. The target building has 5 floors. Figure 18 shows the specifications of the building's analysis model. The input seismic motion was set to 1 / 10 of that of BCJ-L2. The vibration control system 1 of the first embodiment is denoted as Type 1 (lever mechanism type), the vibration control system 1B of the second embodiment is denoted as Type 2 (lever mechanism type with simultaneous synchronization of primary and secondary), and the vibration control system 1C of the third embodiment is denoted as Type 3 (toggle type).

[0055] Figure 19 shows the analysis model of Type 1 (lever mechanism type). The specifications of the inertial mass damper, the cross-sectional area of ​​the cable material, and the specifications of the horizontal spring for period adjustment are as follows. Inertial mass damper specifications: md = 8 tons, cd = 0.005 kNs / mm, kd = 0.054 kN / mm Cross-sectional area of ​​cable material: A = 82 mm² 2 Horizontal spring for period adjustment: 0.135 kN / mm

[0056] Figures 20 to 22 show the response analysis results for Type 1 (lever mechanism type). In the graphs from Figures 20 to 22, BCJ_BARE shows the response analysis results for a building without the damping system 1 (bare frame), and BCJ_DS shows the response analysis results for a building with the Type 1 (lever mechanism type) damping system 1 installed. Figure 23 shows the transfer function of the ground input and the absolute acceleration response at the 5th floor. It can be seen that the installation of the Type 1 (lever mechanism type) damping system 1 reduces the maximum absolute acceleration of the floor in the direction of application, the maximum relative displacement of the floor, and the maximum overturning moment.

[0057] Figure 24 shows the analysis model for Type 2 (lever mechanism type with simultaneous primary and secondary tuning). The specifications for the inertial mass damper, the cross-sectional area of ​​the cable material, and the specifications for the horizontal spring for period adjustment are as follows. Inertial mass damper specifications For primary tuning: md1=8ton, cd1=0.005kNs / mm, kd=0.054kN / mm Inertial mass damper specifications For secondary tuning: md2=8ton, cd2=0.005kNs / mm Cross-sectional area of ​​cable material: A = 82 mm² 2 Horizontal spring for period adjustment: 0.135 kN / mm

[0058] Figures 25 to 27 show the response analysis results for Type 2 (lever mechanism type with simultaneous primary and secondary synchronization). In the graphs from Figures 25 to 27, BCJ_BARE shows the response analysis results for a building without the vibration control system 1B (bare frame), and BCJ_DS shows the response analysis results for a building with Type 2 (lever mechanism type with simultaneous primary and secondary synchronization) installed. Figure 28 shows the transfer function of the ground input and the absolute acceleration response at the 5th floor. It can be seen that the installation of the Type 2 (lever mechanism type with simultaneous primary and secondary synchronization) vibration control system 1B reduces the maximum absolute acceleration of the floor in the direction of application, the maximum relative displacement of the floor, and the maximum overturning moment.

[0059] Figure 29 shows the Type 3 (toggle type) analysis model (bending shear rod model). Figure 30 shows an enlarged view of the base of the analysis model. The Type 3 (toggle type) analysis is an example of applying the Type 3 (toggle type) seismic control system 1C using the open space of a cylindrical building. In the analysis, five Type 3 (toggle type) units arranged radially were adopted. In the Type 3 (toggle type) analysis, the input seismic motion was set to the Hachinohe phase L2 as specified in the regulations. Figure 31 shows the analysis results of the maximum inter-story drift angle response for the Type 3 (toggle type). It can be seen that the maximum inter-story drift angle response is reduced by approximately half when the Type 3 (toggle type) seismic control system 1C is installed.

[0060] Although embodiments of the vibration damping system according to the present invention have been described above, the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the invention. For example, as shown in the vibration control system 1D in Figure 32, cable material 2 may be provided around the perimeter of the building 11, and a displacement direction conversion amplification mechanism 4D and an inertia mass damper 3 may be provided at the top 11a of the building 11. In Figure 32, the displacement direction conversion amplification mechanism 4D is a pulley or lever mechanism. With this configuration, a compressive force P2 acts on the ground due to the reaction force P1 of the cable material 2, which cancels out the uplift force P3 acting on the building 11 and suppresses the overturning of the building 11.

[0061] As shown in Figure 33, a relief mechanism 8 may be provided to prevent excessive load from acting on the inertia mass damper 3, as in the vibration damping system 1E. The relief mechanism 8 is, for example, a device consisting of friction elements. The relief mechanism 8 allows the transmission of load to the inertia mass damper 3 without acting, such as by the restraining force of a spring, until the load acting on the inertia mass damper 3 exceeds a predetermined limit. When the load acting on the inertia mass damper 3 exceeds the predetermined limit, the load acting on the friction elements exceeds the static friction load, causing the friction elements to act and limiting the load transmitted to the inertia mass damper 3, thereby capping it out. In this way, when the inertia mass damper 3 is provided with a relief mechanism 8, the load caps out before an excessive reaction force exceeding the allowable load capacity acts on the inertia mass damper 3, so there is no risk of the inertia mass damper 3 being damaged.

[0062] An inertial mass damper 3 may be connected in parallel to one or a pair of cable materials 2. By adjusting the stiffness of the series-connected spring elements 37, one of the inertial mass dampers 3 may be tuned to one natural vibration mode (e.g., the first natural vibration mode), and the other inertial mass dampers 3 may be tuned to another natural vibration mode (e.g., the second natural vibration mode), thus allowing multiple natural vibration modes to be simultaneously tuned with a combination of one cable material 2 and inertial mass dampers 3.

[0063] In the above embodiment, the cable material 2 is provided so as to extend from the top 11a to the base 11b of the building 11, but it is sufficient if it is provided so as to extend from the upper floors to the lower floors of the building 11, or from the upper part to the lower part of the building 11.

[0064] The Sustainable Development Goals (SDGs) are among the 17 international goals adopted at the UN Summit in September 2015. The vibration control system according to this embodiment can contribute to achieving one of the 17 Sustainable Development Goals (SDGs), such as Goal 11, "Make cities and human settlements inclusive, safe, resilient and sustainable." [Explanation of Symbols]

[0065] 1,1B-E Vibration Control System 2 Cable materials 2a one end 2b Other end 4,4B-4D Displacement Direction Conversion Amplification Mechanism 11 buildings 11a Top 11b base 37 Spring elements θ angle

Claims

1. A tension member that connects the upper and lower parts of a structure and into which tension is introduced, An inertial mass damper provided on the upper or lower part of the aforementioned structure, A vibration damping system comprising a displacement direction conversion and amplification mechanism that converts the displacement of the tensile member into a displacement in the direction of action of the inertial mass damper and amplifies it before inputting it to the inertial mass damper.

2. The vibration damping system according to claim 1, wherein the angle between the axial direction of the tension member and the direction of action of the inertial mass damper is greater than 45° and less than or equal to 90°.

3. The vibration damping system according to claim 1 or 2, wherein the displacement direction conversion amplification mechanism is a lever mechanism connecting the tension member and the inertial mass damper.

4. The vibration damping system according to claim 1 or 2, wherein the displacement direction conversion amplification mechanism is a toggle mechanism connecting the tension member and the inertial mass damper.

5. Multiple tension members are provided at positions symmetrical with respect to the rigid center of the structure. The vibration control system according to claim 1 or 2, wherein the displacement direction conversion amplification mechanism is provided for each of the multiple tension members.

6. Two tension members are provided, positioned symmetrically with respect to the rigid center of the structure. The ends of each of the two tension members connected to the displacement direction conversion amplification mechanism are changed by the displacement direction conversion amplification mechanism to a position extending in the direction of action of the inertial mass damper, and are connected to each other via movable bodies that are movable in the direction of action of the inertial mass damper. The vibration damping system according to claim 5, wherein the inertial mass damper is connected to the moving body.

7. The vibration damping system according to claim 1 or 2, further comprising a spring element connected in series with the inertial mass damper.

8. Multiple inertial mass dampers are provided, The vibration damping system according to claim 7, wherein, among the plurality of inertial mass dampers, one inertial mass damper is set to tune to one natural vibration mode of the structure, and the other inertial mass dampers are set to tune to other natural vibration modes of the structure.

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