JP7433727B2 - Vibration damping device for structures - Google Patents

Description

The present invention particularly relates to a structure vibration damping device for suppressing vibrations of high-rise structures.

Conventionally, as this type of vibration damping device, the one disclosed in Patent Document 1 by the present applicant, for example, is known. This vibration damping device includes a plurality of support members that extend in the vertical direction and are connected between the upper end of a structure such as a high-rise building and the foundation, a mass damper that is connected in series to the lower end of each support member, and A buckling prevention mechanism is provided to prevent buckling of the member.

The support member is composed of a plurality of hollow prismatic pillar members, which are connected via disc springs, so that the tensile rigidity of the support member is set to a smaller value than the compressive rigidity. . The mass damper is, for example, a ball screw type having an inner cylinder, a ball screw, a rotating mass, etc., and the screw shafts of the inner cylinder and the ball screw are connected to the lower end of the support member and the foundation, respectively. In addition, the rotational inertia mass of the rotating mass and the tensile rigidity of the supporting member are set so that the first natural frequency of the additional vibration system determined by them is tuned to the first natural frequency of the structure, and the rotational inertia of the rotating mass The mass and the compression rigidity of the support member are set so that the second natural frequency of the additional vibration system determined by these is tuned to the second natural frequency of the structure.

A plurality of buckling prevention mechanisms are arranged at intervals in the vertical direction, and each is composed of a slab integrally provided to the structure, a sliding plate attached to the slab, and the like. A plurality of rectangular restraint holes are formed at predetermined positions of the slab, and a support member is inserted into each restraint hole. The sliding plates are made of a slippery material, such as a fluororesin, and are attached to the four walls of the restraining hole of the slab. In addition, abutment plates made of stainless steel or the like are pasted on the four outer surfaces of the support member at positions corresponding to the restraint holes, and these abutment plates slightly touch the sliding plates of the restraint holes. They face each other with a gap.

In the above configuration, when the structure vibrates during an earthquake, the upper part of the structure will largely reciprocate (swing) in the lateral direction because bending deformation is superior to shear deformation, especially if the structure is a high-rise structure. . The displacement caused by this rocking is well transmitted to the mass damper via the support member that slides vertically through the restraint hole of the buckling prevention mechanism, causing the rotating mass to rotate and the additional vibration made up of the support member and the mass damper. The system vibrates. As a result, when a tensile load is applied to the support member, the first natural frequency of the additional vibration system is tuned to the first natural frequency of the structure, and when a compressive load is applied, the second natural frequency of the additional vibration system is tuned to the first natural frequency of the structure. is tuned to the secondary natural frequency of the structure, the vibration energy of the structure is absorbed by the additional vibration system, and the vibration of the structure is suppressed.

On the other hand, since the support member is inserted into the restraining hole of the buckling prevention mechanism, the movement of the support member in the horizontal direction is restrained, thereby preventing the support member from buckling when a compressive load is applied.

Patent No. 5399540

In the conventional vibration damping device described above, the buckling prevention mechanism prevents buckling of the support member by restricting horizontal movement of the support member, and prevents buckling of the support member by allowing vertical movement of the support member. , so that the displacement of the structure is well transmitted to the mass damper. However, the buckling prevention mechanism requires a restraining hole into which the support member is inserted, a sliding plate made of fluororesin, etc., and an abutment plate made of stainless steel, etc., and a certain distance in the length direction of the support member. It is necessary to install each. For this reason, as structures become taller and the length of the support members increases, the number of buckling prevention mechanisms installed increases significantly, resulting in a significant increase in the cost of the vibration damping device.

The present invention has been made to solve the above-mentioned problems, and in particular, when the structure is a high-rise structure, it is possible to suppress the vibration of the structure without significantly reducing the vibration damping effect, and also to reduce the vibration of the support member. It is an object of the present invention to provide a vibration damping device for a structure that can significantly reduce costs for preventing buckling.

In order to achieve the above object, the invention according to claim 1 is a vibration damping device for a structure for suppressing vibration of a structure erected on a support, which extends in the vertical direction and connects an upper a supporting member having a lower connecting portion and a lower connecting portion and connected to the structure via the upper connecting portion; a rotary mass that is rotatable and connected to the lower connecting portion of the supporting member and the support; a mass damper that converts displacement of the structure transmitted through the support member into rotational motion of a rotating mass when vibrating, and exhibits a rotational inertial mass effect; A tensile member is connected to one of the upper and lower connecting portions to support a tensile load, and is mechanically separated from the tensile member, and when a compressive load is applied, the upper connecting portion and a compression material for supporting the compressive load in a state in which the other of the lower connecting parts is in contact, and the tensile rigidity of the tension material and the rotational inertia mass of the rotating mass are determined by the response of the primary natural frequency of the structure. The present invention is characterized in that it further includes an anti-buckling material for preventing buckling of the supporting member by being provided in the structure and connected to the compression material.

When a structure vibrates during an earthquake, the bending deformation of the structure is greater than the shear deformation, especially when the structure is high-rise, so the upper part of the structure vibrates in a large lateral direction. Vibrate (swing). According to the configuration of the vibration damping device for a structure of the present invention described above, when the structure swings, the displacement is transmitted to the mass damper via the support member, thereby applying a tensile load and a compressive load to the support member and the mass damper. act alternately, the rotating mass rotates, and the additional vibration system consisting of the support member and the mass damper vibrates while the rotational inertial mass effect is exerted.

During this vibration, the tensile load is supported by the tensile material connected to the upper and lower connections of the support member. In addition, since the tensile rigidity of the tensile material and the rotational inertia mass of the rotating mass are set as described above, when a tensile load is applied, the natural frequency of the added vibration system and the first natural frequency of the structure are tuned. will be held.

On the other hand, when a compressive load is applied, the compressive material, which is mechanically separated from the tensile material and which is connected to one of the upper and lower connecting parts of the support member, is in contact with the other of the upper and lower connecting parts. to support compressive loads. Since the compressive stiffness of the compressed material is not specifically related to the natural frequency of the structure, the natural frequency of the structure is not specifically tuned when a compressive load is applied. However, as mentioned above, when a tensile load is applied, the natural frequency of the added vibration system and the primary natural frequency of the structure are repeatedly tuned, so that the vibration energy of the structure is improved in the added vibration system. Because it is absorbed by

Moreover, buckling of the support member due to compressive load can be effectively prevented by the buckling prevention material. In addition, this anti-buckling material is simply provided in the structure and connected to the compression material, and has a very simple structure compared to conventional buckling prevention mechanisms. The cost for preventing bending can be significantly reduced.

The invention according to claim 2 is the vibration damping device for a structure according to claim 1, characterized in that the compression material has a predetermined compression rigidity larger than the tensile rigidity of the tension material.

According to this configuration, since the compression rigidity of the compression material is set to a predetermined compression rigidity larger than the tensile rigidity of the tension material, the amount of deformation of the support member when a compressive load is applied is suppressed, and the tension material Since the compressed material has a larger cross-sectional shape than the compressed material, buckling of the support member can be made more difficult to occur.

The invention according to claim 3 is the vibration damping device for a structure according to claim 2, in which the tension member is composed of a rod-shaped or wire-shaped steel material, and the compression material is composed of concrete and a steel material other than the rod-shaped or wire-shaped steel material. It is characterized by being comprised of at least one of the following.

According to this configuration, by employing the above-mentioned constituent materials as the tensile material and the compressive material, respectively, the tensile material has a tensile load supporting function, the compressive material has a compressive load supporting function, and the compressive material has a compressive rigidity. The requirement for the stiffness of the support member in claim 2 to be greater than the tensile stiffness of the material can be realized.

The invention according to claim 4 is the vibration damping device for a structure according to any one of claims 1 to 3, wherein the mass damper is such that the damper reaction force generated when a compressive load is applied is a damper that is generated when a tensile load is applied. It is characterized by being an asymmetrical mass damper configured to be smaller than the reaction force.

According to this configuration, when a compressive load is applied, the damper reaction force of the mass damper becomes smaller than when a tensile load is applied, and accordingly, the compressive load on the support member is also reduced. This makes it difficult for the support member to buckle, making it possible to reduce the cross-sectional area and/or the number of buckling prevention materials, further reducing the cost for preventing buckling of the support member. be able to.

The invention according to claim 5 is the vibration damping device for a structure according to any one of claims 1 to 4, wherein the mass damper is constituted by a ball screw type mass damper, and the mass damper is provided in the structure and the mass damper of the support member is The present invention is characterized in that it further includes a twist prevention member for preventing twisting of the support member due to the reaction torque of the mass damper by non-rotatably locking a portion near the connecting portion with the mass damper.

In this configuration, since the mass damper is of a ball screw type, when the mass damper is operated, a reaction torque from the mass damper acts on the support member, causing the support member to be twisted, which may adversely affect its operation. According to this configuration, the portion of the support member near the connecting portion with the mass damper is locked in a non-rotatable manner by the twist prevention material provided on the structure, thereby preventing twisting of the support member due to the reaction torque of the mass damper. , it is possible to ensure smooth operation of the support member.

The invention according to claim 6 is a vibration damping device for a structure according to claim 1 or 2, in which a support member having a symmetrical rigidity with equal stiffness on a compression side and a tension side is used as a support member. The optimal stiffness of the support member that minimizes vibration is calculated based on the fixed point theory, and the compression stiffness of the compression material and the tensile stiffness of the tension material are determined by the natural period on the compression side determined by the compression stiffness and the tensile strength determined by the tensile rigidity. It is characterized in that the additive average value of the natural period on the side is set to be equal to the natural period determined by the calculated optimal stiffness of the support member.

Unlike claim 1, if the supporting member constituting the additional vibration system together with the rotating mass has a symmetrical stiffness with equal stiffness on the compression side and the tension side, the optimal stiffness of the supporting member that minimizes the vibration of the structure is , it is possible to calculate based on fixed point theory. On the other hand, as claimed in claim 1, when the support member has a compression material and a tension material, and the stiffness on the compression side and the tension side are different and the rigidity is asymmetric, the fixed point theory is used to set the optimal stiffness of the support member. It cannot be used directly.

Regarding this point, as will be described later, when using a support member with asymmetrical stiffness, the compression stiffness of the compression material and the tensile stiffness of the tension material are determined by the natural period on the compression side of the added vibration system determined by the compression stiffness, and the tensile stiffness. The additive average value with the natural period on the tension side of the added vibration system determined by is the natural period of the added vibration system determined by the optimal stiffness of the support member based on the fixed point theory, which is calculated when using a support member with symmetrical stiffness. It was confirmed that by setting the values to be equal, a damping effect equivalent to that obtained when using a calculation solution based on fixed point theory for a rigidly symmetrical support member can be obtained. Therefore, according to the above-mentioned structure of claim 6, the compression stiffness of the compressible material and the tensile stiffness of the tensile material can be easily and appropriately set while using the calculation solution based on the fixed point theory in the case of a rigidly symmetrical support member. , it is possible to obtain a good vibration damping effect of the structure.

1 is a diagram schematically showing a vibration damping device according to the present invention together with a structure to which the damping device is applied. FIG. 2 is a diagram showing a planar arrangement of a vibration damping device. FIG. 1 is a diagram showing a vibration damping device according to a first embodiment of the present invention. They are (a) a cross-sectional view of the support member in a tensile state, (b) a cross-sectional view in a compressed state, (c) a cross-sectional view taken along line cc, and (d) a cross-sectional view taken along line dd. It is a figure which shows the rigidity of a support member. 4 is a sectional view of the gear motor type mass damper of FIG. 3. FIG. FIG. 2 is a diagram schematically showing a situation in which a structure oscillates during vibration. It is sectional drawing which shows two other examples of a support member. FIG. 7A is a cross-sectional view showing still another example of the support member in a tensile state, and (b) a cross-sectional view showing the support member in a compressed state. It is a figure which shows the vibration damping device by 2nd Embodiment of this invention. 11 is a sectional view of the ball screw type mass damper of FIG. 10. FIG. It is a figure showing the model of the simulation analysis of a structure and a damping device. It is a figure showing (a) maximum response acceleration and (b) maximum interstory deformation angle obtained by simulation analysis. It is a figure showing the amount of vertical deformation in (a) a symmetric model, and (b) the amount of vertical deformation in an asymmetric model obtained by simulation analysis. It is a diagram showing (a) relative horizontal deformation amount, (b) vertical deformation amount of the entire added vibration system, (c) vertical deformation amount of the mass damper, and (d) vertical deformation amount of the support member obtained by simulation analysis. . FIG. 7 is a cross-sectional view of a mass damper according to a modified example. FIG. 17 is a cross-sectional view showing the check valve of the mass damper of FIG. 16 in (a) a closed position and (b) an open position; 3 is a table showing specifications of the main system used in simulation analysis. It is a table showing the specifications of the additional vibration system used for simulation analysis. FIG. 3 is a diagram showing (a) relative displacement response magnification and (b) absolute acceleration response magnification in the horizontal direction of the main system obtained by simulation analysis.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Structure B shown in FIG. 1 is, for example, a 20-story high-rise building, and is erected on a foundation F set in the ground. The vibration damping device 1 according to the first embodiment includes a plurality of additional vibration systems A1 including a support member 2 and a mass damper 3, and a plurality of anti-buckling members 4 for preventing buckling of the support member 2. The vibration damping device 1 absorbs the vibration energy of the structure B with the additional vibration system A1 by tuning the natural frequency of the additional vibration system A1 to the natural frequency of the structure B that vibrates during an earthquake, etc. It is something to suppress.

As shown in FIGS. 1 and 2, the additional vibration systems A1 are arranged below the center of the structure B, and two systems are provided at each of the four corners of the structure B, for a total of eight systems.

Each support member 2 extends in the vertical direction, and its upper end is connected to a rigid member element S such as a beam provided at the center of the structure B, and its lower end is connected to a mass damper 3. As shown in FIGS. 3 and 4, the support member 2 consists of two steel rods 5, 5 made of PC steel rods as tension materials, concrete 6 and steel pipe 7 as compression materials, and upper and lower ends. It consists of upper and lower connecting members 8 and 9 attached to the.

The concrete 6 is provided integrally inside the steel pipe 7, and both 6 and 7 are fixed between the upper connecting member 8 and the end plate 10 so that the upper and lower ends thereof are flush with each other. Two insertion holes 6a, 6a are formed in the concrete 6 and penetrate in the vertical direction, and a steel rod 5 is passed through each insertion hole 6a. The steel rod 5 has an upper end fixed to the upper connecting member 8 with screws and nuts, has play between the insertion hole 6a of the concrete 6 and the hole of the end plate 10, and has a lower end fixed to the lower connecting member 9 with a screw. and fixed with nuts.

According to the above configuration, since the steel rod 5 and the concrete 6 are separated from each other, when a tensile load is applied to the support member 2, the lower connecting member 9 is connected to the end plate 10 as shown in FIG. 4(a). The steel rod 5 supports (bears) the tensile load while being spaced apart from the steel rod 5 . Therefore, the tensile rigidity K1 of the support member 2 is equal to the tensile rigidity of the steel rod 5.

On the other hand, when a compressive load is applied to the support member 2, as shown in FIG. To support (burden). Therefore, the compressive stiffness K2 of the support member 2 is the sum of the stiffnesses of the concrete 6 and the steel pipe 7, and is larger than the tensile stiffness K1 (see FIG. 5(a)).

The tensile stiffness K1 and compressive stiffness K2 of the support member 2 can be set arbitrarily by changing the number, cross-sectional area and length of the steel rods 5, the cross-sectional area and length of the concrete 6 and the steel pipe 7, etc. This is possible, and in this embodiment, it is set as described later. Furthermore, as long as the desired compressive stiffness K2 of the support member 2 is obtained, one of the concrete 6 and the steel pipe 7 can be omitted.

Alternatively, prestress may be applied to the concrete 6 by applying an introduced axial force to the steel rod 5. FIG. 5(b) shows the rigidity of the support member 2 in that case. When a tensile load is applied, the lower connecting member 9 does not separate from the end plate 10 until the introduced axial force is exceeded. The stiffness will be equal to the compressive stiffness K2.

As shown in FIG. 6, the mass damper 3 is of a gear motor type, and includes a cylinder 12, a piston 13 slidably provided in the cylinder 12 in the axial direction, and a piston rod 14 integrated with the piston 13. , a communication passage 15 connected to the cylinder 12, a gear motor M provided in the communication passage 15, and a rotating mass 31 connected to the gear motor M.

The cylinder 12 has a cylindrical shape, and an internal space defined by a peripheral wall 12a and first and second end walls 12b and 12c is divided by a piston 13 into a first fluid chamber 12d and a second fluid chamber 12e. ing. The communication path 15 always bypasses the piston 13 and communicates with the first and second fluid chambers 12d and 12e. The first and second fluid chambers 12d and 12e and the communication passage 15 are filled with working fluid HF.

Further, a convex portion 12f is integrally provided on the first end wall 12b of the cylinder 12, and a first fixture FL1 is provided on this convex portion 12f via a universal joint (not shown). . The piston rod 14 extends in the axial direction within the cylinder 12, projects to the outside through a rod guide hole 12g in the second end wall 12c, and has a second piston rod at its tip via a universal joint (not shown). A fixture FL2 is provided.

Further, the piston 13 is formed with first and second communication holes 13a and 13b that penetrate in the axial direction. A first relief valve 21 is provided in the first communication hole 13a, and a second relief valve 22 is provided in the second communication hole 13b.

The first relief valve 21 is configured as a normally closed valve, and has a valve body and a spring that biases the valve body in the valve closing direction, so that the pressure of the working fluid HF in the first fluid chamber 12d is maintained at a predetermined level. When the upper limit is reached, the first communication hole 13a is opened. Thereby, the pressure of the working fluid HF in the first fluid chamber 12d is released to the second fluid chamber 12e side, and is limited to the upper limit or less, thereby preventing the pressure from becoming excessive.

The second relief valve 22 is configured similarly to the first relief valve 21, and opens the second communication hole 13b when the pressure of the working fluid HF in the second fluid chamber 12e reaches the above upper limit. By doing so, the pressure in the second fluid chamber 12e is released to the first fluid chamber 12d side, and the pressure in the second fluid chamber 12e is prevented from becoming excessive.

The gear motor M converts the flow of the working fluid HF in the communication path 15 into rotational motion of the rotating mass 31. The gear motor M is, for example, of an external gear type, and includes a casing 32, and a first gear 33 and a second gear 34 housed in the casing 32.

The casing 32 is provided in the communication path 15 and communicates with the communication path 15 via two mutually opposing entrances and exits. Further, the first and second gears 33 and 34 are provided integrally with the first and second rotating shafts 35 and 36, respectively, and mesh with each other. The first and second rotating shafts 35 and 36 are perpendicular to the communication path 15 and extend horizontally. Further, the first rotating shaft 35 protrudes outside the casing 32, and a rotating mass 31 is coaxially and integrally provided at the tip thereof. The rotating mass 31 is made of a material with relatively high specific gravity, such as iron, and is formed into a disk shape.

In the above configuration, when a relative displacement occurs between the cylinder 12 and the piston 13, as the piston 13 slides within the cylinder 12, the working fluid HF flows through the communication path 15, causing the working fluid HF to A viscous damping effect can be obtained. Furthermore, the flow of the working fluid HF is converted into rotational motion by the gear motor M, and the rotating mass 31 rotates, thereby exerting a rotational inertial mass effect by the rotating mass 31.

As shown in FIG. 3, in the mass damper 3 having the above configuration, the cylinder 12 is connected to the foundation F via the first fixture FL1, and the piston 13 is connected to the foundation F via the piston rod 14 and the second fixture FL2. It is connected to the lower connecting member 9 of the support member 2. Note that the connection relationship of the mass damper 3 may be reversed, that is, the piston 13 side may be connected to the foundation F, and the cylinder 12 side may be connected to the support member 2.

Further, the tensile rigidity K1 of the support member 2 of the additional vibration system A1 mentioned above and the specifications of the mass damper 3 (the rotational inertia mass md1 of the rotating mass 31, the viscosity coefficient cd1 of the working fluid HF) are the tensile rigidity K1 and the rotational inertia mass md1. The first natural frequency fd1 (=sqrt(K1/md1)/2π) of the additional vibration system A1 determined by ”). This setting is performed, for example, based on fixed point theory.

On the other hand, the compressive stiffness K2 of the support member 2 is set to a much larger value than the tensile stiffness K1, for example, about three times the tensile stiffness K1, regardless of the natural frequency of the structure B.

Moreover, the plurality of anti-buckling materials 4 are for preventing buckling of the support member 2, and as shown in FIGS. 1 and 2, they are provided every other layer in the structure B, and each It is located near 2. As shown in FIG. 3, the anti-buckling material 4 is made of, for example, an angle material, one end of which is fixed to the structure B, and projects horizontally outward. On the other hand, a gusset plate 7a is integrally provided on the steel pipe 7 of the support member 2 and extends radially outward. The anti-buckling member 4 is connected to the support member 2 by having its tip end bolted to the gusset plate 7a.

Next, the operation of the vibration damping device 1 having the above-described configuration will be explained. When the structure B swings as shown in FIG. 7 during an earthquake or the like, the displacement of the structure B is transmitted to the mass damper 3 via the support member 2. Accordingly, the piston 13 reciprocates with respect to the cylinder 12, and the working fluid HF flows in the communication passage 15, so that the working fluid HF exerts a viscous damping effect, and the flow of the working fluid HF is caused by the gear motor. This is converted into rotational motion by M, and the rotating mass 31 rotates, thereby exerting a rotational inertial mass effect by the rotating mass 31. Further, the additional vibration system A1 consisting of the support member 2 and the mass damper 3 vibrates in a state in which compressive loads and tensile loads are applied repeatedly and alternately to the support member 2.

As described above, the tensile rigidity K1 of the support member 2 and the rotational inertia mass md1 of the mass damper 3 are set so that the first natural frequency fd1 of the additional vibration system A1 is tuned to the first natural frequency of the structure B. ing. As a result, when a tensile load is applied, the natural frequency fd1 of the additional vibration system A1 is tuned to the first natural frequency of the structure B, so that the vibration energy is well absorbed by the additional vibration system A1.

On the other hand, as mentioned above, since the compressive stiffness K2 of the support member 2 is set independently of the natural frequency of the structure B, the tuning by the additional vibration system A1 is not performed when a compressive load is applied; This is repeated as described above upon application of a tensile load. As a result, the vibrations of the structure B can be satisfactorily suppressed without significantly reducing the overall damping effect.

Furthermore, since the horizontal movement of the support member 2 is restrained by the plurality of buckling prevention members 4 arranged in the vertical direction, buckling of the support member 2 due to compressive loads can be effectively prevented. In addition, the buckling prevention member 4 is composed of an angle member connected to the structure B and the support member 2 with bolts or the like, and has a very simple structure compared to conventional buckling prevention mechanisms. The cost for preventing buckling of the support member 2 can be significantly reduced.

8 and 9 show other examples of the support member 2. The support member 2 in FIG. 8(a) is obtained by omitting the end plate 10 from the support member 2 in FIG. 4. With this configuration, the number of parts can be reduced without particularly impairing the function of the support member 2. In the support member 2 of FIG. 8(b), as compared with FIG. 8(a), the steel pipe 7 is made shorter than the concrete 6, and a gap G is provided between the two 6 and 7 to separate them from each other. In this configuration, the steel pipe 7 does not function as a compression material that supports a compressive load, but functions as a sheath for the concrete 6, and contributes to preventing the concrete 6 from buckling.

The supporting member 2 in FIG. 9 is different from the supporting member 2 in FIG. 8(a) by omitting the steel pipe 7, and (a) shows a tensile state and (b) shows a compressed state. Further, in this support member 2, the steel rod 5 is fixed to the concrete 6 using a fixing plate 41, and the upper connecting member 8 is fixed to the concrete 6 using an anchor bolt 42. The steel rod 5 is separated from the concrete 6 at the insertion hole 6a, and the effective length LE contributing to the rigidity of the steel rod 5 is the inner end of the insertion hole 6a, as shown in FIG. 9(a). This is the length from the lower connecting member 9 to the lower connecting member 9.

Next, a vibration damping device 51 according to a second embodiment of the present invention will be described with reference to FIGS. 10 and 11. This vibration damping device 51 differs from the vibration damping device 1 of the first embodiment mainly in that a ball screw type mass damper 53 is used as the mass damper instead of the gear motor type mass damper 3. Hereinafter, the same reference numerals will be given to the same or equivalent components as in the first embodiment, and the description will focus on the parts that are different from the first embodiment.

As shown in FIG. 10, the vibration damping device 51 includes a plurality of additional vibration systems A2 composed of a support member 2 and a ball screw type mass damper 53, and a plurality of additional vibration systems A2 for preventing buckling of the support member 2. A prevention member 4 and a twist prevention member 55 for preventing twisting of the support member 2 due to reaction torque from the mass damper 53 are provided. The configurations of the support member 2 and buckling prevention material 4 are the same as in the first embodiment.

As shown in FIG. 11, the ball screw type mass damper 53 includes an inner cylinder 61, a ball screw 62, a rotating mass 63, and a limiting mechanism 64. The inner cylinder 61 is made of a cylindrical steel material, one end of which is open, and the other end of which is attached to the first flange 65 via a universal joint 65a.

Further, the ball screw 62 has a screw shaft 62a and a nut 62c that is screwed onto the screw shaft 62a via a large number of balls 62b, and is arranged coaxially and in series with the inner cylinder 61. One end of the screw shaft 62a is housed in the inner cylinder 61, and the other end of the screw shaft 62a is attached to the second flange 66 via a universal joint 66a. One end of the nut 62c is fitted into the inner cylinder 61 via a cross roller bearing 67, so that the nut 62c is rotatably supported by the inner cylinder 61.

The rotating mass 63 is made of a material with high specific gravity, such as iron, and is formed into a cylindrical shape. The rotating mass 63 is coaxially arranged outside the inner cylinder 61 and the ball screw 62. An end of the rotating mass 63 on the first flange 65 side is fitted into the inner cylinder 61 via a radial bearing 68, so that the rotating mass 63 is rotatably supported by the inner cylinder 61. Further, a pair of ring-shaped sealing members 69, 69 are provided between the rotating mass 63 and the inner cylinder 61. A space defined by these sealing materials 69, 69, rotating mass 63, and inner cylinder 61 is filled with a viscous material 70 made of silicone oil or the like.

In the above configuration, when a relative displacement occurs between the inner cylinder 61 and the screw shaft 62a, this relative displacement is converted into a rotational movement of the nut 62c by the ball screw 62, and transmitted to the rotating mass 63 via the limiting mechanism 64. As a result, the rotating mass 63 rotates. Thereby, a viscous damping effect by the viscous body 70 disposed between the inner cylinder 61 and the rotating mass 63 is obtained, and a rotational inertial mass effect by the rotating mass 63 is exhibited.

The restriction mechanism 64 restricts the rotational conversion operation of the mass damper 53. The restriction mechanism 64 includes a ring-shaped rotating sliding member 64a disposed between the rotating mass 63 and the nut 62c, a plurality of screws 64b for pressing the rotating sliding member 64a against the nut 62c, and adjusting the pressing force. It is composed of a spring 64c. In this configuration, when the load (axial load) acting in the axial direction of the mass damper 53 reaches the limit load determined according to the degree of tightening of the screw 64b, there is a gap between the rotating sliding member 64a and the nut 62c or the rotating mass 63. The occurrence of slippage limits the rotation conversion operation of the mass damper 53, and prevents the reaction force of the mass damper 53 from becoming excessive.

As shown in FIG. 10, in the mass damper 53 having the above configuration, the inner cylinder 61 is connected to the foundation F via the first flange 65, and the screw shaft 62a of the ball screw 62 is supported via the second flange 66. It is connected to the lower connecting member 9 of the member 2. Note that the connection relationship of the mass damper 53 may be reversed, that is, the ball screw 62 side may be connected to the foundation F, and the inner cylinder 61 side may be connected to the support member 2.

As in the case of the first embodiment, the tensile rigidity K1 of the support member 2 of the additional vibration system A2 mentioned above and the specifications of the mass damper 53 (rotational inertia mass md2 of the rotating mass 63, viscosity coefficient cd2 of the viscous fluid 70) are The first natural frequency fd2 (=sqrt(K1/md2)/2π) of the additional vibration system A2 determined by the rigidity K1 and the rotational inertial mass md2 is set to be tuned to the first natural frequency of the structure B. There is. On the other hand, the compressive stiffness K2 of the support member 2 is set to a much larger value than the tensile stiffness K1, for example, about three times the tensile stiffness K1, regardless of the natural frequency of the structure B.

Further, the twist prevention material 55 is for preventing the support member 2 from twisting due to the reaction torque from the mass damper 53, and is arranged directly above the mass damper 53. As shown in FIG. 10, the twist prevention member 55 is made of, for example, a steel rod, is fixed to the structure B, and projects horizontally outward. On the other hand, a groove 9a extending in the vertical direction is formed on the side surface of the lower connecting member 9 of the support member 2. The tip of the anti-twisting member 55 engages with the groove 9a, thereby locking the support member 2 so as to be movable in the vertical direction but not rotatable. This prevents the support member 2 from twisting due to the reaction torque of the mass damper 53.

Next, the operation of the vibration damping device 51 having the above-described configuration will be explained. When the structure B swings during an earthquake, the displacement of the structure B is transmitted to the mass damper 53 via the support member 2. Along with this, the relative displacement between the inner cylinder 61 and the screw shaft 62b is converted into rotational motion by the ball screw 62, and the rotating mass 63 rotates, so that the viscous damping effect by the viscous body 70 is exerted, and the rotating mass 63, the rotational inertial mass effect is exhibited.

Furthermore, compressive loads and tensile loads are applied repeatedly and alternately to the support member 2, and the additional vibration system A2 consisting of the support member 2 and the mass damper 53 vibrates. As described above, the tensile rigidity K1 of the support member 2 and the rotational inertia mass md2 of the rotating mass 63 are set similarly to the damping device 1 of the first embodiment. Therefore, when a tensile load is applied, the first natural frequency fd2 of the additional vibration system A2 is tuned to the first natural frequency of the structure B, so that the vibration energy of the structure B is well absorbed by the additional vibration system A2. However, as a result, the vibrations of the structure B can be suppressed satisfactorily without significantly reducing the overall vibration damping effect.

Further, since the torsion prevention member 55 provided in the structure B locks the lower connecting member 9 of the support member 2 near the mass damper 53 in a non-rotatable manner, the support member 2 is twisted due to the reaction torque of the mass damper 53. It is possible to prevent this and ensure smooth operation of the support member 2.

Next, with reference to FIGS. 12 to 15, a simulation analysis conducted to confirm the damping effect of the damping device of this embodiment and its results will be described. This simulation analysis is an analysis of the response of structure B when a predetermined seismic wave is input to the foundation F of structure B.

The conditions for the simulation analysis are as follows. As shown in FIG. 12, the analysis model M includes a structure MB, a plurality of additional vibration systems MA including a support member MS and a mass damper MD, and a plurality of anti-buckling members MP.

Structure MB is a building with a large aspect ratio set in the same way as Structure B in Figure 1. Specifically, it is a 20-story building with a size of 6 m x 6 m x 4 m in floor height, and a total height of 76 m. It is. Further, the first natural period TMB1 of the structure MB is common to the X direction and the Y direction, and is approximately 2.6 seconds. A total of eight additional vibration systems MA are arranged below the structure MB from a height of 40 m.

Regarding the mass damper MD, for example, the gear motor type mass damper 3 of the first embodiment shown in FIG. 6 is assumed, and its specifications are: rotational inertia mass md of the rotating mass = 6000 tons, viscosity coefficient cd = 6 of the working fluid. .3kNs/mm, and the limit axial force Fr=1200kN. Regarding the support member MS, in the case where the compressive stiffness K2 is larger than the tensile stiffness K1 corresponding to the present invention (hereinafter referred to as "asymmetric model"), and as a comparative example, the case where the tensile stiffness K1 and the compressive stiffness K2 correspond to the prior art. We set the case where the two are equal (hereinafter referred to as the "symmetric model").

In the asymmetric model, the support member 2 in FIG. 4 is assumed as the support member MS. Specifically, the tensile materials are, for example, two steel rods (round steel) of 72φ and L=40 m, and the tensile rigidity K1 is 41.7 kN/mm. In this case, the first natural period TMA1 of the additional vibration system MA is TMA1=2π・sqrt(md/K1)=approximately 2.4 s, which is approximately equal to the first natural period TMB1 (approximately 2.6 s) of the structure MB. It is set to match and tune in to this.

On the other hand, steel pipes and concrete were used as compression materials, and the stiffness imparting effect of the anti-buckling material MP was taken into consideration, and the compression stiffness K2 was set to 125.4 kN/mm, which was calculated as three times the tensile stiffness K1. Moreover, as the buckling preventive material MP, the buckling preventive material 4 shown in FIG. 3, which simply connects the structure and the support member, was assumed.

On the other hand, in the symmetric model, the support member MS is made of steel, and its tensile stiffness K1 and compressive stiffness K2 are equal to each other and equal to the tensile stiffness K1 (=41.7 kN/mm) of the asymmetric model. I set it like this. In addition, the anti-buckling material MP has a restraining hole into which the support member is inserted, which is the same as the one provided in the conventional vibration damping device described above, and allows the support member to slide in the vertical direction while preventing movement in the horizontal direction. We assumed an anti-buckling material that would restrain the material.

The seismic motion (earthquake wave) input to the foundation F is a sine wave with a period of 2.6 seconds. In addition, as an analysis method, time history response analysis was performed using the average acceleration method, and the damping was of the instantaneous stiffness proportional type, with a damping constant of 2%. In addition to the above-mentioned asymmetric model and symmetric model, as a further comparative example, a simulation analysis was also conducted for a case where no mass damper was provided (hereinafter referred to as "damper-less model"). The results of the simulation analysis will be explained below.

FIG. 13(a) shows the maximum response acceleration AMAX in each layer of the structure MB, and FIG. 13(b) shows the maximum interlayer deformation angle θMAX in each layer of the structure MB. Here, the maximum response acceleration AMAX represents the maximum value of the response acceleration obtained in each layer during input of seismic motion, and the maximum interstory deformation angle θMAX is the maximum value of the interstory deformation angle obtained in each layer during input of seismic motion. represents.

In any model, the maximum response acceleration AMAX is larger toward the upper layer and reaches its maximum at the top layer (20th layer). In addition, the maximum response acceleration AMAX is very large in the model without a damper, approximately 3900 mm/s2 at the top layer, whereas in the asymmetric model and symmetrical model it is 1400 to 1600 mm/s2 at the top layer, and in the model without a damper it is approximately 3900 mm/s2 at the top layer. less than 50% of From the above, it can be seen that with regard to the maximum response acceleration AMAX, the vibration damping effect can be effectively obtained by the additional vibration system composed of the support member and the mass damper.

In addition, there is almost no difference in the maximum response acceleration AMAX between the asymmetric model and the symmetric model across all layers, and it is actually smaller in the asymmetric model. In other words, even when tuning using the added vibration system is performed only on the tension side, a comparable good vibration damping effect can be obtained in terms of maximum response acceleration AMAX compared to when tuning is performed on both the tension and compression sides. I know that it will happen.

On the other hand, the maximum interstory deformation angle θMAX reaches its maximum near the 6th to 9th layers in the model without a damper, and its maximum value is about 2/200 rad, which is very large. On the other hand, in the asymmetric model and the symmetric model, the maximum interstory deformation angle θMAX reaches its maximum near the lower 4 to 7 layers, and the maximum value is about 0.7/200 rad, which is less than 50% of the model without damper. It is. In this way, it can be seen that the vibration damping effect can be effectively obtained with respect to the maximum interstory deformation angle θMAX by the additional vibration system composed of the support member and the mass damper.

In addition, there is almost no difference in the maximum interstory deformation angle θMAX between the asymmetric model and the symmetric model across all layers, and a closer look shows that the asymmetric model is smaller for 9 layers or less, and the symmetric model is smaller for 14 layers or more. is getting smaller. In other words, even when tuning by the additional vibration system is performed only on the tension side, compared to when it is performed on both the tension and compression sides, a comparable good vibration damping effect can be obtained regarding the maximum interlayer deformation angle θMAX. You can see what you can get.

Figures 14(a) and (b) show the time course of the vertical deformation of the support member MS (dotted line), mass damper MD (thin line), and additional vibration system MA (thick line) in the symmetric model and the asymmetric model, respectively. , shown all at once. Here, the amount of deformation of the mass damper MD is the amount of deformation between the lower end position (connection position with the foundation F) L0 and the upper end position (connection position with the support member MS) L1 shown in FIG. 12, and the deformation of the support member MS. The amount of deformation is the amount of deformation between the lower end position (connection position with mass damper MD) L1 and the upper end position L2, and the amount of deformation of the entire additional vibration system MA is the amount of deformation between the lower end position L0 and the upper end position L2. represents.

In addition, Fig. 15(a) shows the relative horizontal deformation of the structure MB (40m above ground), Fig. 15(b) shows the vertical deformation of the additional vibration system MA, and Fig. 15(c) shows the relative deformation of the mass damper. The amount of deformation in the vertical direction of MD and the amount of deformation in the vertical direction of the support member MS are also shown in FIG. 3(d) for the symmetric model (dotted line) and the asymmetric model (solid line), respectively.

The horizontal relative deformation amount shown in FIG. 15(a) is not significantly different between the symmetrical model and the asymmetrical model, and its maximum value is about ±160 mm. It should be noted that at the end of the earthquake motion, there is a slight delay in the phase of the asymmetric model compared to the symmetric model.

Regarding the vertical deformation of the additional vibration system MA, as shown in FIG. 15(c), the amount of deformation of the mass damper MD is approximately equal between the symmetric model and the asymmetric model. In addition, in the symmetric model, the amount of deformation of the mass damper MD is symmetrical on the compression side (positive value side) and the tension side (negative value side), and the maximum value is about ±11 mm, whereas in the asymmetric model , the tension side is slightly larger than the compression side, and the maximum value is about +12 mm on the compression side and about -8 mm on the tension side.

Furthermore, as shown in Fig. 15(d), the amount of deformation of the supporting member MS is large in the symmetric model, and is symmetrical on the compression side and the tension side, and the maximum value is about ±10 mm, whereas the deformation amount on the asymmetric model is large. The model is smaller overall than the symmetrical model and is asymmetrical, with the compression side being smaller than the tension side, with the maximum values being approximately +3 mm on the compression side and approximately -8 mm on the tension side.

As a result of the above, as shown in FIG. 15(b), the deformation amount of the entire additional vibration system MA, which corresponds to the sum of the deformation amount of the mass damper MD and the deformation amount of the support member MS, is The sides are symmetrical with each other, and the maximum value is about ±4 mm, whereas the asymmetric model is symmetrical with each other on the compression and tension sides, and the maximum value is about ±5.5 mm, which is slightly larger than the symmetric model. Large (see Figure 14).

As described above, in the asymmetric model, the amount of deformation of the entire additional vibration system MA is slightly larger than that in the symmetric model, but due to the phase shift effect, the relative amount of deformation in the horizontal direction shown in Fig. 15(a) is They were equivalent. In other words, it was confirmed that the vibration damping device of this embodiment can suppress the vibrations of the structure better without reducing the damping effect much compared to the conventional vibration damping device.

Next, a more detailed method of setting the tensile stiffness K1 and compressive stiffness K2 of the support member MS in the asymmetric model will be described. This setting method calculates the optimal stiffness Kd and natural period Td of the supporting member based on the fixed point theory when an additional vibration system including a symmetrical model supporting member is attached to the structure (main system) as follows. At the same time, the tensile stiffness K1 and compressive stiffness K2 of the asymmetric model are set based on this natural period Td.

First, as shown in FIG. 18, the main system specifications are, for example, mass m=26081 tons, natural period T=5.2 sec, and tower ratio α=6.8.

Assuming that this main system is attached with an additional vibration system including a symmetrical model support member with a mass ratio μ (= equivalent mass (rotational inertial mass) md/main system mass m) of 6.6, Optimal parameters (additional system frequency ratio β, damping constant hd) that minimize the relative displacement response magnification of the system are calculated using the following equations (1) and (2) based on fixed point theory. In addition, based on the calculated optimal parameters, the natural period Td, stiffness Kd (=K1, K2), and damping coefficient cd of the additional vibration system are calculated using the following relational expressions (3) to (5), respectively. Calculated as the original. The above results are shown in case 1 of FIG.

Next, when an additional vibration system including an asymmetric model support member MS whose mass ratio μ and damping constant hd are the same as case 1 is attached to the above main system, the tensile stiffness K1 and compressive stiffness K2 of the support member MS are is calculated using the following relational expressions (6) to (8). That is, the stiffness ratio RK between the compression stiffness K2 and the tensile stiffness K1 is set to a predetermined value (for example, 5), and the average value of the natural period Tdc determined by the compression stiffness K2 and the natural period Tdt determined by the tensile rigidity K1 is The tensile stiffness K1 and the compressive stiffness K2 are calculated so that they are equal to the natural period Td. The above results are shown in case 2 of FIG.

In case 3 of FIG. 19, the stiffness ratio RK is changed from 5 to 10 compared to case 2, and the tensile stiffness K1 and compressive stiffness K2 are calculated in the same way using relational expressions (6) to (8). It is. Furthermore, case 4 is about the added vibration system of the symmetric model, and the mass ratio μ is changed from 6.6 to 3.3 compared to case 1, and case 5 is about the added vibration system of the asymmetric model, which is different from case 4. , tensile stiffness K1 and compressive stiffness K2 were calculated in the same manner.

In order to confirm the vibration damping effect of the additional vibration system in cases 1 to 5 with the specifications set as described above, a simulation analysis was conducted. This simulation analysis targets a simplified one-mass system analysis model in which each additional vibration system is attached to the main system, and analyzes the response of the main system when harmonic ground motion is input.

FIG. 20 shows (a) relative displacement response magnification and (b) absolute acceleration response magnification in the horizontal direction of the main system to ground motion in case 1 and case 2. Further, FIG. 20 also shows cases in which both the tensile rigidity K1 and the compressive rigidity K2 of case 2 are increased by 0.9 times and 1.1 times. From this result, first, when comparing case 1 of the symmetric model and case 2 of the asymmetric model, both resonate near the natural period T (=5.2 sec) of the main system, and the response magnification curves almost overlap, making them equivalent. It was confirmed that a large vibration damping effect can be obtained.

On the other hand, when both the tensile stiffness K1 and the compressive stiffness K2 of case 2 are increased by 0.9 times and 1.1 times, the response magnification is higher near the natural period T of the main system compared to case 2. It can be seen that the damping effect decreases. For example, compared to case 2, the maximum value of the relative displacement response magnification increases to 1.35 times when stiffness K1 and K2 are 0.9 times, and to 1.19 times when stiffness K2 is 1.1 times. ing.

Although not shown, when comparing case 2 and case 3, regardless of the difference in stiffness ratio RK, in both cases, resonance occurs near the natural period T of the main system, and the response magnification curves almost overlap, indicating that the same large It was confirmed that a vibration damping effect can be obtained.

Furthermore, although not shown, in case 4 and case 5, the damping effect is lower due to the smaller mass ratio μ compared to case 1 and case 2, but in both case 4 and case 5, the natural period T of the main system is It was confirmed that the resonance occurred near , the response magnification curves almost overlapped, and the same vibration damping effect was obtained.

As described above, when an additional vibration system including supporting members of a symmetric model is attached to the main system, the optimal stiffness Kd and natural period Td of the supporting members that minimize the vibration of the structure are calculated based on fixed point theory. do. Also, based on this natural period Td, using equations (6) to (8), the tensile stiffness K1 and compressive stiffness K2 of the asymmetric model are calculated as the average value of the natural period Tdt on the tension side and the natural period Tdc on the compression side. is set to be equal to the natural period Td of the symmetric model based on the fixed point theory. As a result, it is possible to obtain a good vibration damping effect equivalent to that obtained when using a calculation solution based on fixed point theory for a support member of a symmetric model. Further, such an effect can be obtained regardless of the mass ratio μ between the equivalent mass md and the main system mass m, and the rigidity ratio RK between the compressive rigidity K2 and the tensile rigidity K1.

Next, a modification of the mass damper will be described with reference to FIGS. 16 and 17. As shown in FIG. 16, this mass damper 73 is of a gear motor type and is used in place of the mass damper 3 of FIG. Furthermore, the mass damper 73 differs from the mass damper 3 in that by adding a check valve 74, the damper reaction force during compression is extremely smaller than that during tension, and is configured as a so-called single-effect damper. Hereinafter, the same reference numerals will be given to the same or equivalent components as those of the mass damper 3, and the explanation will focus on the added check valve 74.

As shown in FIG. 16, a second communication passage 75 is connected to the cylinder 12 in parallel with the communication passage 15, and the second communication passage 75 is provided with a check valve 74. The second communication path 75 always bypasses the piston 13 and communicates with the first and second fluid chambers 12d and 12e.

As shown in FIG. 17, the check valve 74 includes a valve box 74a provided in the second communication path 75 and a rotatable valve body 74d provided within the valve box 74a. The valve box 74a is provided with a first communication port 74b and a second communication port 74c, and the valve box 74a communicates with the second communication path 75 via these communication ports 74b and 74c.

The valve body 74d is disposed within the valve body 74a, rotatably supported by a shaft 74e, and rotates between a closed position shown in FIG. 17(a) and an open position shown in FIG. 17(b). move. The valve body 74d closes the first communication port 74b when it is in the closed position, and opens the first communication port 74b when it is in the open position.

In the above configuration, when a tensile load is applied to the mass damper 73 as the structure B swings during an earthquake, the piston 13 slides toward the second fluid chamber 12e (to the right in FIG. 16). Then, the working fluid HF in the second fluid chamber 12e flows into the second communication passage 75, driving the valve body 74d to the closed position shown in FIG. 17(a). As a result, the flow of the working fluid HF in the second communication path 75 is blocked, and the working fluid HF flows only into the communication path 15, so that a large rotational inertial mass effect by the rotating mass 31 is obtained, and the damper reacts accordingly. Power also increases.

On the other hand, when a compressive load is applied to the mass damper 73, the piston 13 slides toward the first fluid chamber 12d (left side in FIG. 16), so that the working fluid HF in the first fluid chamber 12d is transferred to the second communication path 75. and drives the valve body 74d to the open position shown in FIG. 17(b). As a result, the flow of the working fluid HF in the second communication path 75 is allowed (white arrow in FIGS. 16 and 17(b)), and the flow rate in the communication path 15 is reduced by the amount of flow. The rotational inertial mass effect of the rotating mass 31 is greatly reduced, and the damper reaction force is correspondingly reduced significantly.

As described above, the mass damper 73 is configured as a single-effect damper, and when a compressive load is applied, the damper reaction force is much smaller than when a tensile load is applied, and accordingly, the compressive load on the support member 2 is reduced. significantly reduced. This makes it difficult for the support member 2 to buckle, making it possible to reduce the cross-sectional area and/or the number of buckling prevention members 4, thereby reducing the cost for preventing buckling of the support member 2. It can be further reduced.

In addition, although the above modification is an example in which a gear motor type mass damper is configured with a single-effect damper, a ball screw type mass damper as shown in FIG. 10 may be configured with a single-effect damper. Such a ball screw type single-acting mass damper is disclosed, for example, in Japanese Patent Laid-Open No. 2011-220504 by the applicant as a mass damper in which a one-way clutch is disposed between a ball screw nut and a rotating mass. can be used.

Note that the present invention is not limited to the described embodiments, and can be implemented in various ways. For example, in the embodiment, a PC steel rod is used as the tensile material of the support member 2, but as long as the desired tensile rigidity K1 of the support member 2 is obtained, other PC steel rods such as a PC steel wire or a PC steel stranded wire can be used. It is possible to use steel materials, round steel bars, etc. Among these, PC steel wire is particularly advantageous in that it can be easily handled by unrolling it from a rolled state and letting it hang down when constructing the support member on site.

Furthermore, although concrete, steel pipes, or only concrete are used as the compression material for the support member 2, as described above, any one or more types of construction may be used as long as the desired compression rigidity K2 of the support member 2 is obtained. It is possible to use materials. For example, instead of using concrete, steel pipes or other steel materials such as H steel or flat steel may be used, or steel materials such as H steel may be used in combination with concrete.

Further, in the embodiment, the support member 2 is arranged below the center of the structure B, but the support member 2 is not limited to this, and may be arranged over the entire structure B in the vertical direction, for example. In addition, although the support member 2 of each additional vibration system has been described as being composed of one support member as a whole, the present invention is not limited to this. For example, when the support member 2 is very long, It is possible to configure it with a plurality of connected support members. Furthermore, the number and planar arrangement of the additional vibration systems including the support member 2 and the mass damper are not limited to those shown in the embodiment, and can be changed as appropriate.

Further, in the embodiment, the anti-buckling material 4 is made of an angle material and is fixed to the structure B, but the invention is not limited to this, and the anti-buckling material 4 may be formed integrally with the slab of the structure B. You can. Furthermore, in the embodiment, the anti-buckling materials 4 are arranged every other layer in the structure B, but the installation interval may be changed as appropriate depending on the cross-sectional dimension of the support member 2, the compressive rigidity K2, etc. is possible.

Furthermore, in the embodiment, the compressive rigidity K2 of the support member 2 is set to approximately three times the tensile rigidity K1, but the present invention is not limited to this, and the compressive rigidity K2 may be increased or decreased as long as a good vibration damping effect is obtained. Of course it's a good thing.

Furthermore, in the embodiment, the natural frequency of the additional vibration system determined by the tensile rigidity of the tensile material and the rotational inertia mass of the rotating mass is set to approximately match and synchronize with the primary natural frequency of the structure B. . The setting of the tensile rigidity of the tensile member and the rotational inertia mass of the rotating mass is not limited to such clear tuning as long as it reduces the response of the first natural frequency of the structure B. For example, even if the natural frequency of the additional vibration system determined by these tensile stiffness and rotational inertia mass is relatively apart from the first natural frequency of structure B, the first natural frequency of structure B Any method can be used as long as it effectively reduces the numerical response.

The structure of Structure B is not particularly limited, and may be any of steel frame construction (S construction), reinforced concrete construction (RC construction), steel reinforced concrete construction (SRC construction), concrete-filled steel pipe construction (CFT construction), etc. It is possible to use it as a vibration damping target. The present invention can be particularly effectively applied to steel towers and structures with large aspect ratios. In addition, it is possible to change the detailed structure as appropriate within the scope of the spirit of the present invention.

1 Vibration damping device 2 Support member 3 Mass damper 4 Buckling prevention material 5 Steel bar (tensile material)
6 Concrete (compressed material)
7 Steel pipe (compressed material)
8 Upper connecting member (upper connecting part)
9 Lower connecting member (lower connecting part)
31 Rotating mass 51 Vibration damping device 53 Mass damper (ball screw type mass damper)
55 Anti-twist material 63 Rotating mass 73 Mass damper (asymmetrical mass damper)
B Structure F Foundation (support)
A1 Additional vibration system A2 Additional vibration system K1 Tensile rigidity of supporting member K2 Compressive rigidity md1 of supporting member Rotational inertia mass md2 of rotating mass 31 Rotational inertial mass fd1 of rotating mass 63 First natural frequency (natural frequency) of additional vibration system A1 number)
fd2 First natural frequency (natural frequency) of additional vibration system A2

Claims (6)

A vibration damping device for a structure for suppressing vibration of a structure erected on a support,
a support member that extends in the vertical direction, has an upper connecting portion and a lower connecting portion, and is connected to the structure via the upper connecting portion;
It has a rotating mass that is connected to the lower connecting part of the support member and the support body and is rotatable, and when the structure vibrates, the displacement of the structure transmitted through the support member is Equipped with a mass damper that converts the rotational motion of the rotating mass into rotational inertia mass effect,
The support member is
a tensile material connected to the upper connecting part and the lower connecting part to support a tensile load;
connected to one of the upper connecting part and the lower connecting part, being mechanically separated from the tensile member, and in a state where the other of the upper connecting part and the lower connecting part is in contact when a compressive load is applied; a compression material for supporting a compression load;
The tensile stiffness of the tensile material and the rotational inertia mass of the rotating mass are set to reduce the response of the first natural frequency of the structure,
A vibration damping device for a structure, further comprising an anti-buckling material provided in the structure and connected to the compression material to prevent buckling of the support member. The vibration damping device for a structure according to claim 1, wherein the compression material has a predetermined compression stiffness greater than the tensile stiffness of the tension material. 3. The tensile material is composed of a bar-shaped or wire-shaped steel material, and the compression material is composed of at least one of concrete and a steel material other than a bar-shaped or linear steel material. Vibration damping device for structures .
The structure according to any one of claims 1 to 3, wherein the mass damper is an asymmetrical mass damper that generates a smaller damper reaction force when a compressive load is applied than when a tensile load is applied. Vibration damping device for objects. The mass damper is composed of a ball screw type mass damper,
A torsion prevention member provided on the structure and configured to prevent twisting of the support member due to reaction torque of the mass damper by non-rotatably locking a portion of the support member near a connecting portion with the mass damper. The vibration damping device for a structure according to any one of claims 1 to 4, further comprising:. When using a rigidly symmetrical supporting member having equal rigidity on a compression side and a tensile side as the supporting member, the optimal rigidity of the supporting member that minimizes vibration of the structure is calculated based on a fixed point theory, The compression rigidity of the compression material and the tensile rigidity of the tensile material are determined by the calculated average value of the natural period on the compression side determined by the compression rigidity and the natural period on the tension side determined by the tensile rigidity. 3. The vibration damping device for a structure according to claim 1, wherein the vibration damping device is set to be equal to a natural period determined by the optimum stiffness of the structure.

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