JP2015183723A - Tuned mass damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tuned mass damper that can be detachably and easily attached to a structure such as an already installed rack-type automated warehouse and can absorb vibrations in a plurality of directions with a simple mechanism.SOLUTION: A tuned mass damper comprises: a viscoelastic body having a first face and a second face facing the first face; a mass attached to the first face of the viscoelastic body; and a support frame adapted for attachment to a structure and attached to the second face of the viscoelastic body.

Description

  The present disclosure relates to tuned mass dampers.

  In general, there are three known techniques for reducing the shaking caused by earthquakes such as buildings, rack-type automated warehouses, and fixtures, and preventing these structures from collapsing and falling.

  “Earthquake resistance” refers to a technology that allows a structural member such as a column, a beam, or a wall to withstand an earthquake force in an elastic or elasto-plastic manner with respect to a structure having a strength capable of withstanding an earthquake force. “Seismic isolation” refers to a structure that separates or insulates the structure from the foundation so that seismic vibrations are not directly transmitted to the structure. It is a technology that prevents resonance with earthquake vibration by separating the body and lengthening the natural vibration period of the structure. “Vibration control” refers to a structure that absorbs seismic energy to a damper and weakens the vibration. A damper is installed on each floor or each step or top of a building, rack, etc., and the seismic energy input to the structure is absorbed by the damper. This is a technique for preventing or reducing the vibration and breakage of the structure.

  A tuned mass damper (TMD) is one of the damping devices, and it is structured by adding an additional mass (mass) to the top of the structure and vibrating the mass in a direction opposite to the vibration direction of the structure. Suppress body vibration. The tuned mass damper is used by being attached to the top or each stage of the rack in order to prevent the collapse of the load due to the earthquake or the fall of the pallet in a rack type automatic warehouse or the like.

  Patent Document 1 (Japanese Patent Application Laid-Open No. 2013-180869) states that “a vibration damping device provided in a rack, an additional mass supported so as to be slidable in one horizontal direction, and a displacement of the additional mass in the sliding direction. The rack damping device is characterized in that the additional mass is supported in a non-synchronized state with the natural frequency of the damping object.

  Patent Document 2 (Japanese Patent Laid-Open No. 2013-237542) states that “a pedestal that is detachably attached to a structure and a mass that is supported on the pedestal and is movable in the horizontal direction, the gantry includes the structure. A frame that is bridged between the pillars of the object, a guide that is provided between the frames and that supports the mass in a movable manner, and is rotated around the guide at the first end and the mass at the second end. A damper that is movably attached; a restoration member that is attached to the guide at a first end; and a mass that is attached to the mass at a second end; and an outer side in the vicinity of a joint between the frame and the guide, A vibration damping device including a deployable fixing member that holds a pillar of a structure ”is described.

JP2013-180869A JP2013-237542A

  In a tuned mass damper using an oil damper, the direction of vibration that can be absorbed is limited to the operation direction of the damper. For this reason, the tuned mass damper is usually attached so that the operating direction of the damper substantially matches the direction in which the structure vibrates most. In the case of a structure capable of absorbing vibrations in a plurality of directions, for example, two orthogonal directions, a complicated mechanism is required in addition to the oil damper. For example, in Patent Document 2, a plurality of oil dampers are rotatably attached. When such a complicated mechanism is used, not only the manufacturing cost of the tuned mass damper is increased, but also an extra load not related to vibration absorption is given to the structure.

  The present disclosure provides a tuned mass damper that can be easily attached to and detached from a structure such as an installed rack type automatic warehouse and can absorb vibrations in a plurality of directions with a simple mechanism.

  According to an embodiment of the present disclosure, a viscoelastic body having a first surface and a second surface facing the first surface, a mass attached to the first surface of the viscoelastic body, and a structure A tuned mass damper is provided that includes a gantry frame that is adapted to the attachment of the viscoelastic body and attached to the second surface of the viscoelastic body.

  The tuned mass damper of the present disclosure uses vibrations in a plurality of directions, for example, two directions orthogonal to each other without using a complicated mechanism by using a viscoelastic body as a connecting member and a vibration absorbing member that connect the mass and the structure. Can be absorbed. Moreover, since the mass ratio of the mass in the tuned mass damper can be increased, high vibration absorption performance can be achieved while further reducing the load applied to the structure. Since the tuned mass damper of the present disclosure includes the gantry frame, the tuned mass damper can be attached to and detached from the structure easily.

  The above description should not be regarded as disclosing all embodiments of the present invention and all advantages related to the present invention.

It is a top view of the tuned mass damper of a 1st embodiment of this indication. It is a side view of the tuned mass damper of a 1st embodiment of this indication. It is an expanded side view of the viscoelastic body which comprises the tuned mass damper of 1st Embodiment of this indication. It is a top view of the tuned mass damper of a 2nd embodiment of this indication. It is a side view of the tuned mass damper of a 2nd embodiment of this indication. 2B is a cross-sectional view of a tuned mass damper according to a second embodiment of the present disclosure along plane A in FIG. 2B. FIG. 6 is a graph showing the maximum displacement in the X direction of Example 1A, Example 1B, and Comparative Example 1; It is a graph which shows the displacement reduction rate of the X direction of Example 1A and Example 1B. 6 is a graph showing the maximum acceleration in the X direction of Example 1A, Example 1B, and Comparative Example 1; It is a graph which shows the acceleration reduction rate of the X direction of Example 1A and Example 1B. 6 is a graph showing the maximum displacement in the Y direction of Example 1A, Example 1B, and Comparative Example 1. It is a graph which shows the displacement reduction rate of the Y direction of Example 1A and Example 1B. 6 is a graph showing the maximum acceleration in the Y direction of Example 1A, Example 1B, and Comparative Example 1; It is a graph which shows the acceleration reduction rate of the Y direction of Example 1A and Example 1B. It is a graph which shows the maximum displacement of the X direction of Example 2C, Example 2D, and the comparative example 2. FIG. It is a graph which shows the displacement reduction rate of the X direction of Example 2C and Example 2D. It is a graph which shows the maximum acceleration of the X direction of Example 2C, Example 2D, and Comparative Example 2. It is a graph which shows the acceleration reduction rate of the X direction of Example 2C and Example 2D. It is a graph which shows the maximum displacement of the Y direction of Example 2C, Example 2D, and Comparative Example 2. It is a graph which shows the displacement reduction rate of the Y direction of Example 2C and Example 2D. It is a graph which shows the maximum acceleration of the Y direction of Example 2C, Example 2D, and Comparative Example 2. It is a graph which shows the acceleration reduction rate of the Y direction of Example 2C and Example 2D.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings for the purpose of illustrating representative embodiments of the present invention. However, the present invention is not limited to these embodiments. In the accompanying drawings, elements having the same reference numerals are intended to have the same configuration or function.

  A tuned mass damper according to an embodiment of the present disclosure includes a viscoelastic body having a first surface and a second surface facing the first surface, a mass attached to the first surface of the viscoelastic body, and a structure A gantry frame adapted to be attached to the body and attached to the second surface of the viscoelastic body.

  FIG. 1A is a top view of the tuned mass damper according to the first embodiment of the present disclosure. The tuned mass damper 1 includes a mass 10, a viscoelastic body 20, and a gantry frame 30, and can absorb vibrations in the X direction and the Y direction that are orthogonal to each other. FIG. 1A also shows a mass support member 40 which is an optional component. The rack type automatic warehouse includes a brace 2 supported by a protruding portion 4 attached to a column 3. Two adjacent arms 2 that are separated from each other, and four columns 3 to which these two arms 2 are attached via a protruding portion 4 define a cargo compartment, and the arms 2 are used for placing a pallet. . The tuned mass damper 1 is installed in a rack-type automatic warehouse via a gantry frame 30 so as to bridge two adjacent arms 2 separated from each other. The mass 10 is deformed by the deformation of the viscoelastic body 20 in the X direction and the Y direction. It can move in the direction. The tuned mass damper 1 may be provided at the top of a rack type automatic warehouse, or may be provided at an arbitrary level (loading room).

  Although a plurality of viscoelastic bodies 20 are shown in FIG. 1A, in another embodiment, only one viscoelastic body may be included in the tuned mass damper. In this case, the viscoelastic body is attached to the mass so that the center of the viscoelastic body matches the center of gravity of the mass. As shown in FIG. 1A, when a plurality of viscoelastic bodies 20 are attached to the mass 10, it is desirable that these viscoelastic bodies are arranged symmetrically around the center of gravity of the mass. As shown in FIG. 1A, it is desirable that the mass support members 40 that are optional components are alternately arranged with the elastic bodies 20 symmetrically around the center of gravity of the mass.

  FIG. 1B is a side view of the tuned mass damper according to the first embodiment of the present disclosure shown in FIG. 1A as viewed from the Y direction. As shown in FIG. 1B, in the tuned mass damper 1 according to the first embodiment of the present disclosure, the mass 10 is located above the viscoelastic body 20. Since the tuned mass damper of the first embodiment can make the structure of the gantry frame relatively simple, it is possible to reduce the profile (thin) or to reduce the weight of members other than the mass. Such a reduction in profile or weight reduction is particularly advantageous when there are restrictions on the installation space, the load resistance of the structure, and the like. The mass 10 includes a plurality of metal plates 11 fixed by a binding screw 12 and nuts 13. As the metal plate 11, a steel plate, a stainless steel plate, or the like is generally used in consideration of a unit price per mass, strength, durability, and the like. You may perform a shot blast process to a metal plate. In an embodiment in which a plurality of metal plates are used as a mass, the mass of the mass can be changed after the tuned mass damper is installed in accordance with a change in the use state of the luggage compartment, for example, a change in the amount of luggage. In another embodiment, the mass can be composed of one metal plate or one metal block. As a material constituting the mass, other materials or structures such as concrete and liquid enclosure can be used.

  The shape of the mass may vary, but it is desirable that it be symmetrical about the mass center of gravity or about the mass center of gravity. For example, when the thickness and material of the mass are substantially constant throughout, the planar shape of the mass viewed from the vertical direction is a circle, a square, a rectangle, a hexagon, or a shape obtained by cutting off the corners of these polygons. be able to. The mass of the mass can be determined in consideration of the total mass (including luggage) of the structure on which the tuned mass damper is installed, the strength and the natural frequency, the viscoelastic characteristics of the viscoelastic body, and the like. The mass of the mass can be, for example, about 1% or more, or about 5% or more, about 30% or less, or about 20% or less of the total mass of the structure. When a plurality of tuned mass dampers are installed in one structure, the total mass of the masses included in the plurality of tuned mass dampers is, for example, about 1% or more of the total mass of the structure, or about 5% or more. It can be about 30% or less, or about 20% or less. When the structure is a general rack type automatic warehouse, the mass of the mass can be, for example, about 100 kg or more, or about 200 kg or more, about 2000 kg or less, or about 1500 kg or less.

  The gantry frame 30 is attached to the rack type automatic warehouse by fitting the arms 2 into the recesses of the fixing jig 31. The fixing jig 31 is fixed to the bottom surface of the gantry frame 30 with mounting screws 32 and nuts 33. As an alternative embodiment, the fixing jig may be formed integrally with the gantry frame. The gantry frame and the fixing jig are generally formed of steel, fiber reinforced plastic or the like in consideration of strength, durability and the like.

  FIG. 1C is an enlarged side view of the viscoelastic body 20 shown in FIG. 1B. The viscoelastic body 20 includes a plurality of viscoelastic material layers 21 and an intermediate support plate 22 interposed between these viscoelastic material layers. The uppermost viscoelastic material layer 21 is bonded to the mass mounting plate 23, and the lowermost viscoelastic material layer 21 is bonded to the gantry frame mounting plate 24. The mass mounting plate 23 is fixed to the mass 10 by mounting screws 25. The gantry frame mounting plate 24 is fixed to the gantry frame 30 by mounting screws 26 and nuts 27.

  The intermediate support plate, mass mounting plate, and gantry frame mounting plate are preferably materials having strength and rigidity, and are metal plates including iron materials such as steel plates, stainless steel plates, aluminum-plated steel plates, galvanized steel plates, and epoxy-coated steel plates. Or a metal plate such as zinc, aluminum or titanium. These metal plates may be subjected to chemical surface treatment such as mechanical surface treatment such as shot blasting or primer treatment. A viscoelastic body can also be comprised with one viscoelastic material layer, without using an intermediate | middle support plate. When the material which comprises a viscoelastic material layer has adhesiveness, a viscoelastic material layer can be adhere | attached on these plates in direct contact with a mass attachment plate, a mount frame attachment plate, and / or an intermediate | middle support plate. You may adhere | attach a viscoelastic material layer on a mass attachment plate, a mount frame attachment plate, and / or an intermediate | middle support plate using an adhesive agent separately. The viscoelastic material layer can be directly bonded to the mass and / or the gantry frame as a viscoelastic body without using the mass mounting plate and / or the gantry frame mounting plate.

  The viscoelastic material layer may be composed of a single viscoelastic material sheet or a laminate of a plurality of viscoelastic material sheets. The laminated body of viscoelastic material sheets may be a laminate in which a plurality of viscoelastic material sheets are brought into contact with each other, and a double-sided adhesive film may be interposed between these viscoelastic material sheets. The viscoelastic material layer undergoes shear deformation when the mass is displaced in the horizontal direction with respect to the structure due to vibration such as an earthquake. When the viscoelastic material layer undergoes shear deformation, friction occurs between molecules of the viscoelastic material, and vibration energy is converted into heat. In this way, the viscoelastic body including the viscoelastic material absorbs vibration energy by friction between molecules of the viscoelastic material. Any material having the above action can be used as the viscoelastic material. For example, an acrylic polymer (for example, poly (meth) acrylate, or a copolymer of (meth) acrylate and acrylic acid, acrylamide, etc.), Polymer materials such as urethane polymers (for example, polyether urethane and polyester urethane), olefin polymers, silicone polymers (for example, methyl vinyl silicone), vinyl chloride polymers, butane rubber, and butyl rubber are advantageously used. be able to. In the present specification, (meth) acrylate means acrylate and methacrylate, and (meth) acryloyl means acryloyl and methacryloyl.

  In one embodiment of the present disclosure, acrylic polymers are advantageously used as the viscoelastic material. As a monomer constituting the acrylic polymer, for example, a (meth) acrylic monomer having a linear or branched alkyl group having 14 to 22 carbon atoms (hereinafter also referred to as C14-22 (meth) acrylic monomer), for example, Examples include isostearyl (meth) acrylate, cetyl (meth) acrylate, n-stearyl (meth) acrylate, n-behenyl (meth) acrylate, isomyristyl (meth) acrylate, and isopalmityl (meth) acrylate.

  Monomers include unsaturated monocarboxylic acids (eg, acrylic acid, methacrylic acid, etc.), unsaturated dicarboxylic acids (eg, maleic acid, itaconic acid, etc.), ω-carboxypolycaprolactone monoacrylate, monohydroxyethyl phthalate (meth) A carboxyl group-containing monomer such as acrylate, β-carboxyethyl acrylate, 2- (meth) acryloyloxyethyl succinic acid, or 2- (meth) acryloyloxyethyl hexahydrophthalic acid may be included. Monomers are difunctional or polyfunctional (meth) acrylates (e.g. 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri ( Crosslinkable monomers such as (meth) acrylate, pentaerythritol tetra (meth) acrylate, etc.) may also be included.

  For example, when the monomer includes a C14-22 (meth) acryl monomer and a carboxyl group-containing monomer, the carboxyl group-containing monomer is about 1 part by mass or more with respect to about 100 parts by mass of the C14-22 (meth) acryl monomer. It can be about 10 parts by mass or less. By setting the amount of the carboxyl group-containing monomer to about 1 part by mass or more with respect to about 100 parts by mass of the C14-22 (meth) acrylic monomer, the cohesive force of the viscoelastic material is increased and the shear storage elasticity of the viscoelastic body is increased. The rate G ′ can be advantageously increased. In addition, the loss coefficient η of the viscoelastic body can be increased, and a tuned mass damper having excellent vibration absorption characteristics can be provided. On the other hand, by making the amount of the carboxyl group-containing monomer about 10 parts by mass or less with respect to about 100 parts by mass of C14-22 (meth) acrylic monomer, the temperature dependence of the viscoelastic property of the viscoelastic material is reduced. Stable damping performance can be obtained over a wide temperature range.

  The weight average molecular weight of the acrylic polymer may be in the range of about 10,000 or more and about 2 million or less. By setting the weight average molecular weight within the above range, the elastic modulus of the viscoelastic material is suitable for a tuned mass damper, and the heat resistance of the viscoelastic material can be increased, and the tuned has high reliability over a long period of time. Mass dampers can be provided.

  Viscoelastic materials include tackifier resins such as rosin resins, modified rosin resins (hydrogenated rosin resins, disproportionated rosin resins, polymerized rosin resins, etc.), terpene resins, terpenes, in addition to the polymers described above. A phenol resin, an aromatic modified terpene resin, a petroleum resin, a coumarone resin, and the like may be included. The viscoelastic material may contain additives such as thickeners, thixotropic agents, extenders, fillers and the like.

  The thickness of the viscoelastic body can be appropriately determined according to the mass of the mass (that is, the load applied to the viscoelastic body), the maximum displacement amount, and the like. Since the viscoelastic material layer substantially contributes to vibration absorption in the viscoelastic body, the thickness of the viscoelastic material layer (the total thickness when using a plurality of viscoelastic material layers) is, for example, about 10 mm or more, Or about 20 mm or more, about 500 mm or less, or about 200 mm or less. The thickness per layer of the viscoelastic material layer can be, for example, about 2 mm or more, or about 5 mm or more, about 50 mm or less, or about 20 mm or less.

  The amount of shear strain of the viscoelastic body is related to the maximum displacement of the mass. The amount of shear strain of the viscoelastic body can generally be about 100% or more, or about 200% or more, about 2000% or less, or about 1000% or less of the thickness of the viscoelastic body. The maximum displacement of the mass can be, for example, about 1 cm or more, about 5 cm or more, or about 10 cm or more, about 50 cm or less, about 30 cm or less, or about 20 cm or less.

  The cross section parallel to the first surface of the viscoelastic body (that is, the cross section parallel to the mounting surface of the mass) desirably has a rotationally symmetric shape such as a circle, a square, or a regular hexagon, and is particularly preferably a circle. Since the cross section parallel to the first surface of the viscoelastic body has a rotationally symmetric shape, uniform vibration absorption characteristics can be exhibited in a plurality of directions parallel to the first surface. In an embodiment, in a cross section parallel to the first surface of the viscoelastic body, the viscoelastic material layer and the optional intermediate support plate have a rotationally symmetric shape such as a circle, a square, a regular hexagon, and the viscoelastic material layer and The center of rotation of any intermediate support plate is coincident. The viscoelastic material layer desirably has the same cross section in the vertical direction.

The shear area of the viscoelastic body (the total shear area when a plurality of viscoelastic bodies are used for one mass) depends on the mass of the mass (that is, the load applied to the viscoelastic body) and the maximum displacement. Can be determined as appropriate. Since the viscoelastic material layer is the softest among the structural elements of the viscoelastic body, the shear area of the viscoelastic material layer can be determined with respect to the mass of the mass so that the viscoelastic material layer does not creep or break. desirable. On the other hand, it is desirable to determine the shear area of the viscoelastic material layer so as not to disturb the mass movement excessively. In one embodiment, the shear area of the viscoelastic material layer (when using a plurality of viscoelastic bodies for one mass, the total shear area of the viscoelastic material layers) is, for example, a surface pressure applied by the mass of the mass. It is determined to be about 100 kPa or more, or about 200 kPa or more, about 3 MPa or less, or about 2 MPa or less. In another embodiment, the shear area of the viscoelastic material layer (when a plurality of viscoelastic bodies are used for one mass, the total shear area of the viscoelastic material layers) is, for example, a maximum displacement amount of the mass is about In the case of ± 10 mm to about ± 300 mm, it is about 10 cm ² or more, or about 20 cm ² or more, about 500 cm ² or less, or about 200 cm ² or less.

The viscoelastic properties of the viscoelastic body can be defined by the shear storage modulus G ′ and the loss coefficient η. The shear storage modulus G ′ of the viscoelastic body is, for example, about 1 × 10 ³ Pa or more, about 5 × 10 ³ Pa or more, or about 1 × 10 ⁴ Pa or more, about 2.5 × at 20 ° C. and 1 Hz. 10 ⁶ Pa or less, about 1 × 10 ⁶ Pa or less, or about 2.5 × 10 ⁵ or less. The loss factor η of the viscoelastic body is, for example, about 0.4 or more, or about 0.5 or more, about 2 or less, or about 1.5 or less at 20 ° C. and 1 Hz. The above-mentioned shear storage elastic modulus is small compared to the shear storage elastic modulus (generally about 3 × 10 ⁵ Pa to ⁵ × 10 ⁷ Pa) of an elastic material such as a natural rubber system used for the seismic isolation device, The loss factor η is considerably larger than the loss factor (generally 0.15 to 0.25) of an elastic material such as a high damping rubber used in the seismic isolation device. The viscoelastic properties of the viscoelastic body used in the tuned mass dampers of these embodiments are completely different from the viscoelastic properties required for the seismic isolation device.

The damper stiffness of the tuned mass damper can be, for example, about 0.02 kN / cm or more, or about 0.1 kN / cm or more, about 100 kN / cm or less, or about 10 kN / cm or less. The damper viscosity coefficient of the tuned mass damper is, for example, about 0.003 kN · s / cm or more, or about 0.01 kN · s / cm or more, about 25 kN · s / cm or less, or about 2.5 kN · s / cm or less. It can be. The damper stiffness and the damper viscosity coefficient are calculated from the following equations.
Damper rigidity = (G ′ × As) / t
Damper viscosity coefficient = [(0.5 × T / π) × η × G ′] × As / t
In the formula, G ′ is the shear storage modulus (Pa) of the viscoelastic body, η is the loss coefficient of the viscoelastic body, As is the total shear area (cm ² ) of the viscoelastic body, and t is the thickness of the viscoelastic body ( cm) and T indicate the period (s).

It is desirable that the natural frequency (period) of the tuned mass damper substantially coincides with the natural frequency of the structure, for example, the natural frequency in at least one direction of the rack type automatic warehouse in which the luggage is disposed. By using a viscoelastic material with low frequency dependence of viscoelastic properties for a viscoelastic body, it has excellent vibration damping performance in any of these multiple directions in a structure having different natural frequencies in multiple directions. It can be demonstrated. For example, the shear storage modulus G ′ of a viscoelastic body using such a viscoelastic material is, for example, about 1 × 10 ³ Pa or more, about 5 × 10 ³ Pa or more at 20 ° C., 1 Hz, and 5 Hz. Or about 1 × 10 ⁴ Pa or more, about 2.5 × 10 ⁶ Pa or less, about 1 × 10 ⁶ Pa or less, or about 2.5 × 10 ⁵ or less, and the loss factor η is, for example, 20 ° C., At both 1 Hz and 5 Hz, it is about 0.4 or more, or about 0.5 or more, about 2 or less, or about 1.5 or less. In some embodiments, an acrylic polymer can be used in which the monomer type and formulation are designed to have such viscoelastic properties.

  Referring again to FIG. 1B, the mass support member 40, which is an optional component, includes a hemispherical sliding portion 41 and is fixed to the gantry frame 30 with mounting screws 42. The mass support member can reduce the compressive stress applied to the viscoelastic body and prevent creep of the viscoelastic material layer. The hemispherical sliding part may be a ball bearing and may be provided with a surface coating such as a fluororesin. You may attach a mass support member to a mass and may make a sliding part contact a mount frame. The friction coefficient of the contact surface between the sliding portion of the mass support member and the mass or the gantry frame is preferably about 0.1 or less, or about 0.08 or less.

  The mass support member can also be used as a limiter for determining the maximum displacement amount of the mass. In this embodiment, when a part of the viscoelastic body deformed in a certain direction comes into contact with the mass support member, further deformation of the viscoelastic body along that direction is suppressed, and the moving mass stops. To do. The limiter can prevent irreversible deformation and breakage of the viscoelastic body. In another embodiment, a separate limiter (not shown) can be provided on the cradle frame and / or mass. For example, a hollow cylindrical member surrounding the viscoelastic body can be used as the limiter. In yet another embodiment, a limiter may be provided on the gantry frame and a stopper configured to contact the limiter may be provided on the mass. In this embodiment, when the stopper contacts the limiter, the moving mass can be stopped.

  A combination of a mass and a viscoelastic body may be used as one damper unit, and a plurality of damper units having different damper rigidity may be stacked in the vertical direction. In this embodiment, a plurality of damper units are stacked so that the damper rigidity increases from the top to the bottom, and the limiter is arranged so that the damper units are sequentially operated from the top as the frequency increases. It is possible to exhibit damping performance with respect to various frequencies.

  FIG. 2A is a top view of a tuned mass damper according to a second embodiment of the present disclosure. The tuned mass damper 101 includes a mass 110, a viscoelastic body 120, and a gantry frame 130, and can absorb vibrations in the orthogonal X and Y directions. Similar to FIG. 1A, the rack type automatic warehouse includes arms 102 supported by a protruding portion 104 attached to the support column 103, two adjacent arms 102 that are separated from each other, and these two arms 102. Four struts 103 attached through the galling-out portion 104 define a luggage compartment, and the arm 102 is used for placing a pallet. The tuned mass damper 101 is installed in a rack-type automatic warehouse via a gantry frame 130 so as to bridge two adjacent arms 102 separated from each other. The mass 110 is deformed by the deformation of the viscoelastic body 120 in the X direction and the Y direction. It can move in the direction. The tuned mass damper 101 may be provided at the top of a rack-type automatic warehouse, or may be provided at an arbitrary stage (loading room).

  Although a plurality of viscoelastic bodies 120 are shown in FIG. 2A, in another embodiment, only one viscoelastic body may be included in the tuned mass damper. In this case, the viscoelastic body is attached to the mass so that the center of the viscoelastic body matches the center of gravity of the mass. As shown in FIG. 2A, when a plurality of viscoelastic bodies 120 are attached to the mass 110, it is desirable that these viscoelastic bodies are arranged symmetrically around the center of gravity of the mass.

  FIG. 2B is a side view of the tuned mass damper according to the second embodiment of the present disclosure shown in FIG. 2A as viewed from the Y direction. As shown in FIG. 2B, in the tuned mass damper according to the second embodiment of the present disclosure, the mass 110 is positioned below the viscoelastic body 120. The mass 110 includes a plurality of metal plates 111 fixed by welding, adhesion, or the like. As the metal plate 111, what was demonstrated in 1st Embodiment can be used. In another embodiment, the mass can be composed of one metal plate or one metal block. As a material constituting the mass, other materials or structures such as concrete and liquid enclosure can be used.

  The shape and mass of the mass that can be used for the tuned mass damper of the second embodiment are as described in the first embodiment.

  In the tuned mass damper 101 of the second embodiment shown in FIGS. 2A and 2B, the gantry frame 130 has a cage shape constituted by a combination of a plurality of frame members 134 extending in the horizontal direction or the vertical direction. You may arrange | position a wall using the steel plate, a plastic plate, etc. between the some frame member 134 which comprises the mount frame 130. FIG. In this embodiment, the mass mounting plate 123 is fixed to the mass 110 by the mounting screws 125, and the gantry frame mounting plate 124 is fixed to the frame member 134 that extends in the horizontal direction above the gantry frame 130 by the mounting screws 126. The viscoelastic body 120 is attached to the mass 110 and the gantry frame 130.

  The gantry frame 130 is attached to the rack type automatic warehouse by fitting the arms 102 into the recesses of the fixing jig 131. The fixing jig 131 is fixed to the bottom surface of the frame member 134 that extends in the horizontal direction below the gantry frame 130 by means of mounting screws 132 and nuts 133. As an alternative embodiment, the fixing jig may be formed integrally with the gantry frame. The frame member and the fixing jig constituting the gantry frame are generally formed of steel, fiber reinforced plastic or the like in consideration of strength, durability and the like.

  Structure, material, dimensions (thickness, shear area, etc.), shape, and characteristics (shear strain amount, shear) of viscoelastic body or components of viscoelastic body that can be used for the tuned mass damper of the second embodiment The storage elastic modulus G ′, loss coefficient η, etc.) are as described in the first embodiment. For example, the viscoelastic body 20 shown in FIG. 1C can be used as the viscoelastic body 120 of the tuned mass damper 101 of the second embodiment.

  Referring back to FIG. 2B, the mass support member 140, which is an optional component having the hemispherical sliding portion 141, is fixed to the bottom surface of the mass 110 with the mounting screw 142. The mass support member can reduce the tensile stress applied to the viscoelastic body and prevent the viscoelastic material layer from being broken, peeled off, irreversibly deformed, and the like. When the viscoelastic body has a sufficient strength to suspend and hold the mass, the mass support member may not be used. The mass support members are desirably arranged symmetrically around the center of gravity of the mass. The hemispherical sliding part may be a ball bearing and may be provided with a surface coating such as a fluororesin. You may attach a mass support member to a mount frame, and may make a sliding part contact a mass. The friction coefficient of the contact surface between the sliding portion of the mass support member and the gantry frame or mass is desirably about 0.1 or less, or about 0.08 or less. In FIG. 2B, the sliding portion 141 of the mass support member 140 contacts and slides on the grating 135 attached to the frame member 134 extending in the horizontal direction at the bottom of the gantry frame 130. Instead of the grating, the sliding portion of the mass support member may slide on a plate member having a smooth flat surface such as a steel plate.

  In FIG. 2B, a limiter 150 is installed at the bottom of the gantry frame 130, and a stopper 151 is attached to the bottom surface of the mass 110. The limiter 150 and the stopper 151 determine the maximum displacement amount of the mass. As the viscoelastic body is deformed, the stopper 151 moves toward the limiter 150, and when the stopper 151 comes into contact with the limiter 150, further deformation of the viscoelastic body along that direction is suppressed, and the stopper 151 moves thereby. The trout is stopped. By using the limiter and the stopper, irreversible deformation and breakage of the viscoelastic body can be prevented. The limiter and the stopper may be formed integrally with the mass and the gantry frame, respectively. The mass support member can also be used as a stopper.

  FIG. 2C shows a cross-sectional view of tuned mass damper 101 along plane A in FIG. 2B. FIG. 2C shows four mass support members 140 arranged symmetrically around the center of mass of the mass 110, four limiters 150 and four stoppers 151 corresponding thereto, and a grating 135 represented by a dotted diagonal grid. It is shown.

  The characteristics of the tuned mass damper of the second embodiment, such as damper rigidity, damper viscosity coefficient, natural frequency (period), and the like are as described in the first embodiment. The tuned mass damper of this embodiment can easily increase the maximum displacement of the mass as compared with the tuned mass damper of the first embodiment. The maximum displacement amount of the tuned mass damper of the second embodiment can be, for example, about 5 cm or more, about 10 cm or more, or about 20 cm or more, about 100 cm or less, about 50 cm or less, or about 30 cm or less. Increasing the maximum displacement of the mass in this manner is advantageous for use in a structure having a large amplitude at the top of the structure, such as an elongated structure.

  The tuned mass damper of the present invention can be used for various structures such as buildings and fixtures in addition to the rack type automatic warehouse described above. In addition to earthquakes, various vibrations caused by environmental vibrations such as winds such as typhoons, automobiles, railways, factories, and production equipment can be absorbed.

  The embodiments of the present disclosure will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited thereto.

  The vibration absorption characteristic of the tuned mass damper of the present disclosure was analyzed using SNAP LE manufactured by Structural System Co., Ltd. as analysis software.

  Table 1 shows the specifications of tuned mass damper (TMD) types A to D used in the analysis.

  Table 2 shows the parameters of the structural models 1 and 2 used for the analysis. In the structural models 1 and 2, the long side direction is the X direction and the short side direction is the Y direction.

  Table 3 shows the vibration conditions used for the analysis.

  The analysis results using tuned mass damper types A and B for the structural model 1 are shown in Table 4 and FIGS. 3A to 3H.

  The analysis results using the tuned mass damper types C and D for the structural model 2 are shown in Table 5 and FIGS. 4A to 4H.

  As can be seen from Tables 4 and 5, FIGS. 3A to 3H, and FIGS. 4A to 4H, each of the TUD mass damper types A to D has an X direction (long side direction) and a Y direction (short) with different natural periods. Excellent vibration control effect in both directions. The tuned mass damper types C and D in which the mass is positioned below the viscoelastic body are particularly advantageous for structures having a large amplitude at the top in one or more directions because of the elongated shape, such as the structural model 2. it can.

  The above description is illustrative, and the present invention is not limited to the above-described embodiments and modifications unless the features of the present invention are impaired. The constituent elements of the above-described embodiments and modifications include those that can be replaced and that are obvious for replacement while maintaining the identity of the invention. That is, other forms conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. It is also possible to arbitrarily combine one or a plurality of the above embodiments and modified examples.

DESCRIPTION OF SYMBOLS 1,101 Tuned mass damper 2,102 Arm 3,103 Post 4,104 Projecting part 10,110 Mass 11,111 Metal plate 12 Tightening screw 13,27,33,133 Nut 20,120 Viscoelastic body 21 Viscoelasticity Material layer 22 Intermediate support plate 23, 123 Mass mounting plate 24, 124 Mounting frame mounting plate 25, 26, 32, 42, 125, 126, 132, 142 Mounting screw 30, 130 Mounting frame 31, 131 Fixing jig 134 Frame Member 135 Grating 40, 140 Mass support member 41, 141 Sliding part 150 Limiter 151 Stopper

Claims (8)

  A viscoelastic body having a first surface and a second surface opposite to the first surface; a mass attached to the first surface of the viscoelastic body; and the viscoelasticity adapted for attachment to a structure. A tuned mass damper comprising a gantry frame attached to the second surface of the body.   The tuned mass damper according to claim 1, wherein the mass is located above the viscoelastic body.   The tuned mass damper according to claim 1, wherein the mass is located below the viscoelastic body.   The tuned mass damper according to any one of claims 1 to 3, wherein a cross section of the viscoelastic body parallel to the first surface has a rotationally symmetric shape. The tuned mass damper according to any one of claims 1 to 4, wherein a storage elastic modulus G ′ of the viscoelastic body at 20 ° C. and 1 Hz is 1 × 10 ³ Pa to 2.5 × 10 ⁶ Pa.   The tuned mass damper according to any one of claims 1 to 5, wherein the viscoelastic body includes an acrylic polymer.   The tuned mass damper according to any one of claims 1 to 6, further comprising a mass support member arranged between the mass and the gantry frame.   The tuned mass damper according to any one of claims 1 to 7, further comprising a plurality of viscoelastic bodies, wherein the plurality of viscoelastic bodies are arranged symmetrically around the center of gravity of the mass.

Images