Method for setting specifications of vibration damping device

Abstract

To set specifications while suppressing antiresonance in a vibration control device having a plurality of tuned mass dampers.SOLUTION: A step of assuming that the plurality of tuned mass dampers 14 are sequentially installed on the structural member 52, setting a natural frequency of the tuned mass damper 14 assumed to be installed first to a primary natural frequency of the structural member 52, and then obtaining a frequency of anti-resonance generated by one or the plurality of tuned mass dampers 14 assumed to be installed first; And a process of correcting the natural frequency of one or a plurality of tuned mass dampers 14 assumed to be previously installed to the frequency of the antiresonance obtained in the process, and setting the natural frequency of the tuned mass damper 14 assumed to be installed next.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for setting specifications of a vibration damping device. [Background technology]

[0002] Patent Document 1 discloses a technology relating to a vibration control device that forms a secondary vibration system for an architectural structure such as a house, and that can exert a dynamic vibration-absorbing effect on the architectural structure, which is the primary vibration system. In this prior art, a plurality of divided secondary vibration systems are formed using a plurality of divided masses of the same mass, and when tuning the natural frequencies of each of these divided secondary vibration systems to mutually different values, the minimum and maximum natural frequencies of the plurality of divided secondary vibration systems are set so that the ratios of the minimum and maximum natural frequencies to the natural frequency of the architectural structure to be isolated are mutually reciprocals, and the natural frequencies of all the divided secondary vibration systems are set so that they form a geometric progression with respect to each other.

[0003] Patent Document 2 discloses technology related to a system for installing a vibration control device that acts as a secondary vibration system for a house, which is the main vibration system, in a house, particularly a divided-mass dynamic damper in which multiple divided masses are each elastically supported by rubber mounts. In this prior art, a divided-mass dynamic damper is prepared for each house frequency range predetermined within a range of 2 to 8 Hz, with the number of divisions being 2 to 8, and standardized so that each natural frequency increases or decreases in increments within a range of 0.1 to 0.8 Hz. A standardized divided-mass dynamic damper is selected from the house frequency range that includes the house's natural frequency and installed in the house as is. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-74089 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-120069 Summary of the Invention [Problem to be solved by the invention]

[0005] A vibration control device with multiple tuned mass dampers can reduce vibration over a wider range of frequencies than a vibration control device with a single tuned mass damper. However, the use of multiple tuned mass dampers can cause anti-resonance.

[0006] In view of the above, an object of the present invention is to set specifications of a vibration control device having a plurality of tuned mass dampers while suppressing anti-resonance. [Means for solving the problem]

[0007] The first aspect is a method for setting the specifications of a vibration control device having a plurality of tuned mass dampers, which repeats the following steps: assuming that the plurality of tuned mass dampers will be installed in order on an object to be vibration-controlled, setting the natural frequency of the tuned mass damper assumed to be installed first to the primary natural frequency of the object to be vibration-controlled, and then determining the anti-resonance frequency generated by one or more of the tuned mass dampers assumed to be installed first; and correcting the natural frequency of the one or more tuned mass dampers assumed to be installed first to the anti-resonance frequency determined in the previous step, and setting the natural frequency of the tuned mass damper assumed to be installed next.

[0008] In the first aspect of the method for setting the specifications of a vibration damping device, multiple tuned mass dampers with different natural frequencies are provided, thereby achieving vibration reduction effects over a wide range of frequencies. The tuned mass dampers are then assumed to be installed in sequence on the object to be damped, and the previously assumed tuned mass dampers are corrected to match the anti-resonance frequency generated by the previously assumed tuned mass dampers, while the natural frequency of the next assumed tuned mass damper is set, thereby suppressing anti-resonance.

[0009] A second aspect is a method for setting the specifications of a vibration control device according to the first aspect, in which the anti-resonance frequency is determined by the following steps: calculating the primary natural frequency and effective mass of the object to be vibration-controlled using the finite element method; creating a single-mass model of the object to be vibration-controlled from the calculated primary natural frequency and effective mass; creating a multi-mass model by adding the tuned mass damper, which is assumed to be installed, to the single-mass model; inputting a sweep wave into the multi-mass model to calculate the response acceleration; and Fourier transforming the calculated response acceleration.

[0010] In the second method for setting the specifications of a vibration control device, a multi-mass model is created by sequentially adding tuned mass dampers to a single-mass model of the object to be damped. A sweep wave is then input into the multi-mass model to calculate the response acceleration, and the calculated response acceleration is then Fourier transformed to determine the anti-resonance frequency. This makes it easy to determine the anti-resonance frequency resulting from the sequential addition of tuned mass dampers. [Effects of the Invention]

[0011] According to the present invention, it is possible to set the specifications while suppressing anti-resonance in a vibration control device having a plurality of tuned mass dampers. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a plan view showing a vibration damping device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a front view of the vibration damping device shown in FIG. [Figure 3] 3 is a vertical cross-sectional view of a connecting member constituting the vibration damping device of FIG. 1, taken along the line III-III of FIG. 4. [Figure 4] FIG. 4 is a plan view of the connecting member of FIG. 3. [Figure 5] (A) is a single mass model of a structural material, and (B) is a multi-mass model of a structural material with a vibration control device installed. [Figure 6] FIG. 1 is an explanatory diagram illustrating a method for setting natural frequencies by sequentially installing tuned mass dampers on structural materials, using a multi-mass model. [Figure 7] This is a table of specifications for each tuned mass damper step. [Figure 8] 6 is a graph showing the resonance frequency characteristics of the one mass model of FIG. 5(A). [Figure 9] (A) is a graph showing the resonance frequency characteristics of the one-mass model of Figure 5(A) and the multi-mass model of Figure 6(A), and (B) is a graph showing the resonance frequency characteristics of the multi-mass model of Figure 6(A). [Figure 10] (A) is a graph showing the resonant frequency characteristics of the one-mass model of Figure 5(A), the multi-mass model of Figure 6(A), and the multi-mass model of Figure 6(B), and (B) is a graph showing the resonant frequency characteristics of the multi-mass model of Figure 6(B). [Figure 11] (A) is a graph showing the resonant frequency characteristics of the single mass model of Figure 5(A), the multi-mass model of Figure 6(A), the multi-mass model of Figure 6(B), and the multi-mass model of Figure 6(C), and (B) is a graph showing the resonant frequency characteristics of the multi-mass model of Figure 6(C). [Figure 12] (A) is a graph showing the resonant frequency characteristics of the single mass model of Figure 5(A), the multi-mass model of Figure 6(A), the multi-mass model of Figure 6(B), the multi-mass model of Figure 6(C), and the multi-mass model of Figure 6(D), and (B) is a graph showing the resonant frequency characteristics of the multi-mass model of Figure 6(D). [Figure 13] This is a three-dimensional model of a building. [Figure 14] 1 is a graph showing a sweep wave. [Figure 15] 10 is a graph showing response acceleration. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Embodiment> This section explains how to set the specifications of a vibration control device with multiple tuned mass dampers. The two directions that intersect at right angles to the horizontal direction are the X and Y directions, and are indicated by arrows X and Y, respectively. The vertical direction that is perpendicular to the X and Y directions is the Z direction, and is indicated by arrow Z. The front-to-back direction is the Y direction, and the left-to-right direction is the X direction.

[0014] [Vibration control device] First, the structure of a vibration damping device having multiple tuned mass dampers will be described. Note that the vibration damping device of this embodiment has a configuration in which four tuned mass dampers are integrally provided, but the present invention is not limited to this.

[0015] A tuned mass damper is a device that suppresses resonance around the natural frequency of an object by adding a mass to the object via a spring, etc. From another perspective, a tuned mass damper is a device that reduces the vibration of the object by vibrating a mass that takes over the vibration of the object.

[0016] 1 and 2 show a vibration damping device 10 as one embodiment of the present invention. The vibration damping device 10 has a structure in which a plurality of tuned mass dampers 14 are attached to a support base 12.

[0017] As shown in FIG. 1 , the support base 12 has a structure in which four first beams 16 extending in the front-rear direction are arranged between two second beams 18 extending in the left-right direction. Both the first beams 16 and the second beams 18 extend linearly and are made of high-rigidity steel, which in this embodiment are H-shaped steel. The four first beams 16 are arranged in parallel and spaced apart from each other in the left-right direction. The two second beams 18 are arranged in parallel and spaced apart from each other in the front-rear direction. The support base 12 is constructed by fixing both ends of each first beam 16 to one of the second beams 18 by means of welding, bolts, or the like.

[0018] 1 and 2, the tuned mass damper 14 damps vibrations in the vertical direction of a building 50 and has a structure in which a single mass member 20 is supported by multiple connecting members 22. The mass member 20 is in the shape of a substantially rectangular block and is preferably made of a material with a high specific gravity, such as iron. The length of the mass member 20 in the left-right direction is greater than the distance between adjacent first beam members 16.

[0019] The length of the mass member 20 in the front-to-rear direction is smaller than half the distance between the two second beams 18. Screw holes (not shown) that open to the underside are formed in the square portions of the mass member 20. Four of these screw holes are provided in each corner of the mass member 20, and are positioned to correspond to the bolt holes 36 of the mounting flange member 34, which will be described later.

[0020] The mass of the mass member 20 is set taking into consideration the mass of the object to be damped, the frequency of the vibration to be damped, and the vertical spring constant of the connecting member 22. In this embodiment, the entire mass member 20 is shaped like a single block, but it is also possible to form the mass member 20 by, for example, stacking and fixing multiple metal plates together, and the mass of the mass member 20 can be adjusted by changing the number of metal plates stacked together.

[0021] 3 and 4, the connecting member 22 is a composite structure having a structure in which an elastomer 26 serving as another elastic material is fixed to a metal coil spring 24 serving as an elastic material. The connecting member 22 includes a spring element and a damping element, and the spring element is made up of the metal coil spring 24 and the elastomer 26, and the damping element is made up of the elastomer 26.

[0022] As shown in Fig. 3, the metal coil spring 24 has a structure in which a spring wire 28 made of spring steel extends in a spiral shape. In the metal coil spring 24, both axial end portions of the spring wire 28 are formed as large diameter portions 30 in which the winding diameter is larger than that of the axial center portion of the spring wire 28. In this embodiment, the large diameter portions 30 of the spring wire 28 are provided over approximately the entire circumference at the axial end portions of the metal coil spring 24. In the metal coil spring 24 of this embodiment, the cross-sectional shape of the spring wire 28 is approximately circular and is approximately constant along the length of the spring wire 28.

[0023] The cross-sectional shape and cross-sectional area of ​​the spring wire 28 of the metal coil spring 24 may vary along the length, and the cross-sectional shape is not limited to a circle. In addition, both end portions of the metal coil spring 24 may be ground, and the surfaces that come into contact with the mounting flange member 34 (described later) are made flat, thereby preventing the metal coil spring 24 from tilting.

[0024] The elastomer 26 is fixed to the surface of the metal coil spring 24, and has a cylindrical hollow structure corresponding to the metal coil spring 24 as a whole, with a central hole 31 that penetrates in the vertical direction. The elastomer 26 is fixed so as to cover the entire surface of the spring wire 28 of the metal coil spring 24, and the metal coil spring 24 is disposed in an embedded state inside the elastomer 26.

[0025] Furthermore, the portion of the elastomer 26 that covers the outer periphery of the metal coil spring 24 is thicker than the portion that covers the inner periphery. The elastomer 26 is made of, for example, rubber or a resin elastomer and has rubber-like elasticity. The elastomer 26 is preferably made of a material that provides a large energy damping effect based on internal friction or the like through elastic deformation, and in this embodiment is made of rubber. The elastomer 26 may also be made of, for example, a material that has many bubbles inside, such as foam rubber.

[0026] Because the vertically intermediate portion of the metal coil spring 24 that is outside the large diameter portion 30 has a smaller diameter than the large diameter portion 30, the vertically intermediate portion of the elastomer 26 fixed to the metal coil spring 24 has a smaller diameter. As a result, the vertical spring constant of the elastomer 26 is smaller than when the entire vertical portion has a large diameter corresponding to the portion fixed to the large diameter portion 30, and it is possible to set a low vertical spring characteristic for the connecting member 22.

[0027] The elastomer 26 has groove-shaped lightening portions 32 that open to the inner circumferential surface between the pitches of the spring wire 28 of the metal coil spring 24. The lightening portions 32 extend spirally along the winding direction of the spring wire 28 of the metal coil spring 24. Due to the formation of the lightening portions 32, the elastomer 26 is thinned in the radial direction between the pitches of the spring wire 28, thereby reducing the compression spring constant in the up-down direction, which is the axial direction. The deepest portions of the lightening portions 32 are located further outward than the axial center portion of the metal coil spring 24 excluding the large diameter portion 30. In other words, the spaces between adjacent spring wires 28 in the coil axial direction of the metal coil spring 24 are not continuously filled with the elastomer 26 in the axial direction.

[0028] In the metal coil spring 24, the pitches between adjacent spring wires 28 in the vertical direction are connected by the elastomer 26. In this embodiment, the formation of the lightening holes 32 allows the pitches between the spring wires 28 to be connected by the elastomer 26 on the outer periphery of the spring wires 28.

[0029] Mounting flange members 34a, 34b are fixed to both axial ends of the elastomer 26. The lower mounting flange member is 34a, and the upper mounting flange member is 34b. When there is no need to distinguish between the two, they will be referred to as mounting flange member 34. The mounting flange member 34 is a generally rectangular plate with rounded corners, and is generally square in shape when viewed from above and below, with the length of each side being greater than the winding diameter of the large-diameter portion 30 of the metal coil spring 24.

[0030] Bolt holes 36 are formed in each of the square portions of the mounting flange member 34 as bolt fixing portions that penetrate in the vertical direction (see also FIG. 4). In this embodiment, the bolt holes 36 are circular holes (see also FIG. 4). The four bolt holes 36 are located on an imaginary circle that is concentric with the metal coil spring 24 and are equidistant from the central axis of the metal coil spring 24. The four bolt holes 36 are also located on diagonal lines of the mounting flange member 34, and the intersection of the diagonal lines of the mounting flange member 34 is located on the central axis of the metal coil spring 24 (see also FIG. 4).

[0031] A circular through-hole 38 that penetrates vertically is formed in the center of the mounting flange member 34. The through-hole 38a in one mounting flange member 34a has a larger diameter than the through-hole 38b (see also FIG. 4) in the other mounting flange member 34b, and a ring-shaped metal fitting 40 that is separate from the mounting flange member 34a is press-fitted and fixed into the through-hole 38a.

[0032] The elastomer 26, with the metal coil spring 24 disposed therein, has both axial ends fixed to the mounting flange members 34a, 34b. The elastomer 26 is vulcanization bonded to the mounting flange members 34a, 34b at locations outer than the through holes 38a, 38b. The axial ends of the elastomer 26, which has a large diameter due to being fixed to the large diameter portion 30 of the metal coil spring 24, are fixed to the mounting flange members 34, thereby improving the bonding strength. The bolt holes 36 provided in each square portion of the mounting flange members 34a, 34b are both located outer than the elastomer 26 and are exposed without being covered by the elastomer 26.

[0033] Furthermore, because the elastomer 26 interposed between the overlapping surfaces of the metal coil spring 24 and the mounting flange member 34 is made sufficiently thin, the elastomer 26 between the overlapping surfaces has almost no effect on the spring or damping characteristics, and the characteristics are approximately the same as if the metal coil spring 24 and the mounting flange member 34 were directly overlapped, so the metal coil spring 24 and the mounting flange member 34 can be considered to be directly connected.

[0034] 1 and 2, the connecting members 22 are attached to the mass member 20. That is, bolts 42 are inserted through bolt holes 36 in the mounting flange member 34b and screwed into threaded holes (not shown) that open on the underside of the mass member 20, thereby fixing the upper end of the connecting members 22 to the mass member 20. Four connecting members 22 are attached in parallel to the square portion of one mass member 20. In this way, the square portion of the mass member 20 is elastically supported by the four connecting members 22 to form the tuned mass damper 14.

[0035] Preferably, the four connecting members 22 constituting one tuned mass damper 14 have the same spring characteristics. Furthermore, it is desirable that the four connecting members 22 are common members with the same shape, size, structure, and material. This ensures that the mass of the mass member 20 is evenly supported by the four connecting members 22. This prevents problems such as the mass member 20's support load being concentrated on a specific connecting member 22 or the mass member 20 vibrating unintentionally when vibration is input. Alternatively, for example, a connecting member 22 with the required spring characteristics may be selected from multiple types of connecting members 22 prepared in advance, each with different spring characteristics, and the four selected connecting members 22 with the same spring characteristics may be attached to one mass member 20.

[0036] The tuned mass damper 14 constitutes a secondary vibration system by being attached to the support base 12. That is, the lower ends of the connecting members 22 that constitute the tuned mass damper 14 are fixed to the support base 12 by inserting bolts 44 into bolt holes 36 in the mounting flange member 34a into bolt holes (not shown) in the support base 12 and screwing them into nuts (not shown).

[0037] Of the four connecting members 22 attached to the mass member 20, two are attached to each of the first beams 16, and the other two are attached to the second beams 18. The mass member 20 is directly and elastically supported on the support base 12 by both the metal coil springs 24 and the elastomer 26 that make up the connecting members 22. In other words, the metal coil springs 24 and the elastomer 26 of the connecting members 22 are arranged in parallel in the vertical direction, which is the support direction of the mass member 20, and each connects the mass member 20 to the support base 12.

[0038] In this embodiment, four tuned mass dampers 14 are attached to the support base 12 at intervals in the front-to-back and left-to-right directions. This configures the vibration damping device 10 as a TMD (Tuned Mass Damper) equipped with four sub-vibration systems. Attaching the four tuned mass dampers 14 to the support base 12 makes it possible to reduce the mass of the mass member 20 of each tuned mass damper 14 while ensuring a sufficient mass for the entire vibration damping device 10. This simplifies the attachment of the tuned mass dampers 14 to the support base 12, and also simplifies the manufacture, storage, and transportation of the tuned mass dampers 14.

[0039] 2, the vibration damping device 10 having such a structure is attached to a building 50 by fixedly attaching the support base 12 to a structural member 52 such as a floor structural member that constitutes the building 50, which is the main vibration system. There are no particular limitations on the method for attaching the support base 12 to the structural member 52, but for example, the support base 12 can be attached to the structural member 52 by bolting or welding.

[0040] Since the vibration control device 10 has a unit structure in which multiple tuned mass dampers 14 are integrated by the support base 12, by connecting the support base 12 to a structural material 52 that vibrates greatly due to a resonance phenomenon, it is possible to directly apply the vibration control effect of the tuned mass dampers 14 to the structural material 52.

[0041] Furthermore, by appropriately setting the shape and size of the support base 12, it is possible to set the installation space for the mass member 20 and other components at a position away from the structural material 52 that is the target of vibration damping, thereby improving design flexibility. Furthermore, because the support base 12 stably supports the multiple tuned mass dampers 14, the tuned mass dampers 14 can be stably attached to the structural material 52 in a horizontal position, regardless of the shape or structure of the attachment location of the vibration control device 10 on the structural material 52.

[0042] When vertical vibrations are exerted on the structural member 52 to which the vibration control device 10 is attached, the vertical vibrations input from the structural member 52 to the support base 12 are transmitted to the mass member 20 via the connecting member 22, causing the mass member 20 to be displaced in the vertical direction. The kinetic energy of the mass member 20, which is converted from the vibration energy of the vibration to be controlled, is absorbed by the energy damping action of the elastomer 26 that constitutes the connecting member 22. In this way, the dynamic vibration absorption action of the secondary vibration system (tuned mass damper 14) that constitutes the vibration control device 10 reduces the vertical (up-down) vibrations of the structural member 52, which is the target of vibration control, and ultimately of the building 50.

[0043] Each tuned mass damper 14 actively displaces the mass member 20 in a resonant state when vibration of a natural frequency predetermined by the mass of the mass member 20 and the spring constant of the connecting member 22 is input, thereby providing an excellent vibration-damping effect through the dynamic vibration-absorbing action described above. On the other hand, for input vibrations of frequencies outside the natural frequency, the displacement of the mass member 20 may be small, resulting in an ineffective vibration-damping effect. Therefore, the four tuned mass dampers 14 that make up the vibration damping device 10 have different vertical natural frequencies (resonant frequencies of the mass-spring system). This allows the four tuned mass dampers 14 to exert a vibration-damping effect against multiple types of vibration with different frequencies, thereby realizing the vibration damping device 10 as a TMD with vibration-damping performance for input vibrations over a wider frequency range.

[0044] One way to differentiate the natural frequencies of the four tuned mass dampers 14 is to differentiate the masses of the mass members 20 of each tuned mass damper 14, but it is preferable to differentiate the spring characteristics of the connecting members 22 of each tuned mass damper 14. This makes it possible to obtain multiple types of tuned mass dampers 14 with different natural frequencies while using a common large-sized mass member 20. In this embodiment, the four mass members 20 have the same mass, and the connecting members 22 of each tuned mass damper 14 have different spring characteristics in the vertical direction, so that the four tuned mass dampers 14 have different natural frequencies in the vertical direction.

[0045] Note that when the four tuned mass dampers 14 are made to have different natural frequencies, it is not necessary that all four tuned mass dampers 14 have different natural frequencies. For example, two of the four tuned mass dampers 14 may be tuned to the same natural frequency, with the natural frequencies of two of the tuned mass dampers 14 being different from those of the other two tuned mass dampers 14.

[0046] The connecting member 22 of the tuned mass damper 14 has a structure in which an elastomer 26 is fixed to the entire surface of a metal coil spring 24, and is structured to integrally include a spring element and a damping element.

[0047] The connecting member 22 has a simpler structure and can be installed in a smaller installation space than conventional vibration control devices that separately provide a spring element and a damper. Furthermore, by adjusting the resonant frequency of the mass-spring system (secondary vibration system) using the connecting member 22 as a spring according to the natural frequency of the building 50, which is the primary vibration system, the secondary vibration system can efficiently reduce vibrations in the resonant frequency range of the primary vibration system. Because the connecting member 22 is a composite structure that has the metal coil spring 24 and the elastomer 26 in parallel (rather than in series) between the primary vibration system and the secondary vibration system, the resonant frequency of the secondary vibration system can be adjusted not only by the spring characteristics of the metal coil spring 24 but also by the spring characteristics of the elastomer 26, providing greater flexibility in tuning the resonant frequency.

[0048] [How to set vibration control device specifications] Next, a method for setting the specifications of the vibration control device 10 having a plurality of tuned mass dampers 14, four in this example, will be described.

[0049] Specifically, this method involves setting the natural frequency of each of the four tuned mass dampers 14 before installing the vibration control device 10 on the structural members 52 of the building 50. In this example, the natural frequency of each tuned mass damper 14 is set by differentiating the spring characteristics of the connecting members 22, but the present invention is not limited to this.

[0050] FIG. 5(A) shows a one-mass model MD(0) that represents the state before the vibration damping device 10 is installed on a structural material 52, which is the object to be damped. The natural frequency of the structural material 52 in this one-mass model MD(0) is 9.2 Hz. m0 is the mass of the structural material 52, which is 1500 kg in this example. k0 is the spring constant, which is 29100 kN / m in this example. h is the damping constant, which is 5% in this example. In this example, the structural material 52 is a reinforced concrete slab (see FIG. 13), but is not limited to this. Methods for calculating the natural frequency of the structural material 52 and modeling it will be described later.

[0051] 5(B) is a diagram of a multi-mass model MD(3) showing the state in which the vibration damping device 10 is installed on a structural member 52. The tuned mass dampers 14 in the vibration damping device 10 are designated as the first TMD 14A, the second TMD 14B, the third TMD 14C, and the fourth TMD 14D. In the figure, m1 is the mass of the mass member 20 of the first TMD 14A, m2 is the mass of the mass member 20 of the second TMD 14B, m3 is the mass of the mass member 20 of the third TMD 14C, and m4 is the mass of the mass member 20 of the fourth TMD 14D. Additionally, k1 is the spring constant of the connecting member 22 of the first TMD 14A, k2 is the spring constant of the connecting member 22 of the second TMD 14B, k3 is the spring constant of the connecting member 22 of the third TMD 14C, and k4 is the spring constant of the connecting member 22 of the fourth TMD 14D. In this example, the masses m1, m2, m3, and m4 of the mass member 20 are all 375 kg. In this example, the spring constants k1, k2, k3, and k4 of the connecting member 22 are changed to set a desired natural frequency.

[0052] 6A to 6D are explanatory diagrams illustrating a method for setting the natural frequencies of the first TMD 14A, the second TMD 14B, the third TMD 14C, and the fourth TMD 14D, which are tuned mass dampers in the vibration damping device 10.

[0053] 7 is a table showing the natural frequencies for each step of the method for setting the natural frequencies of the first TMD 14A, second TMD 14B, third TMD 14C, and fourth TMD 14D, which are the tuned mass dampers in the vibration control device 10. As mentioned above, h is the damping constant.

[0054] Figure 8 is a graph of the resonant frequency characteristics of the one-mass model MD(0) in Figure 5(A). As mentioned above, in this graph, the primary natural frequency of the structural material 52 is 9.2 Hz, so there is a peak at 9.2 Hz. This graph is referred to as frequency characteristics (0).

[0055] In step 1, the natural frequency of the first TMD 14A of the vibration damping device 10 is set to 9.2 Hz, which is the primary natural frequency of the structural member 52 (see FIG. 7).

[0056] FIG. 6(A) shows a multi-mass model MD(1) when it is assumed that the first TMD 14A, whose natural frequency is set to 9.2 Hz in step 1, is installed on the structural member 52.

[0057] Figures 9(A) and 9(B) are graphs of the resonant frequency characteristics of this multi-mass model MD(1). Note that Figure 9(A) illustrates both the single-mass model MD(0) and the multi-mass model MD(1), while Figure 9(B) illustrates only the multi-mass model MD(1). From these graphs, it can be seen that by installing the first TMD 14A, the vibration of the structural material 52's primary natural frequency of 9.2 Hz is reduced, but anti-resonances HK1A and HK1B occur. The peak frequency of anti-resonance HK1A is 8.25 Hz, and the peak frequency of anti-resonance HK1B is 10.25 Hz.

[0058] In step 2, the natural frequency of the first TMD 14A of the vibration damping device 10 is corrected to 8.25 Hz, which is the peak frequency of anti-resonance HK1A, and the natural frequency of the second TMD 14B is set to 10.25 Hz, which is the peak frequency of anti-resonance HK1B (see FIG. 7).

[0059] Figure 6(B) shows the multi-mass model MD(2) assuming that a first TMD 14A with a natural frequency of 8.25 Hz and a second TMD 14B with a natural frequency of 10.25 Hz are installed on the structural material 52 in step 2.

[0060] Figures 10(A) and 10(B) are graphs of the resonant frequency characteristics of this multi-mass model MD(2). Note that Figure 10(A) illustrates three models: the single-mass model MD(0), the multi-mass model MD(1), and the multi-mass model MD(2), while Figure 10(B) illustrates only the multi-mass model MD(2). These graphs reveal that the installation of the first TMD 14A and the second TMD 14B generates anti-resonances HK2A, HK2B, and HK2C. The peak frequency of anti-resonance HK2A is 7.625 Hz, the peak frequency of anti-resonance HK2B is 9.125 Hz, and the peak frequency of anti-resonance HK2C is 11.125 Hz.

[0061] In step 3, the natural frequency of the first TMD 14A of the vibration damping device 10 is corrected to 7.625 Hz, which is the peak frequency of anti-resonance HK2A, the natural frequency of the second TMD 14B is corrected to 9.125 Hz, which is the peak frequency of anti-resonance HK2B, and the natural frequency of the third TMD 14C is set to 11.125 Hz, which is the peak frequency of anti-resonance HK2C (see FIG. 7).

[0062] Figure 6(C) shows the multi-mass model MD(3) assuming that the first TMD 14A, whose natural frequency was set to 7.625 Hz in step 3, the second TMD 14B, whose natural frequency was set to 9.125 Hz, and the third TMD 14C, whose natural frequency was set to 11.125 Hz, are installed on the structural material 52.

[0063] Figures 11(A) and 11(B) are graphs of the resonant frequency characteristics of this multi-mass model MD(3). Note that Figure 11(A) illustrates four models: the single-mass model MD(0), the multi-mass model MD(1), the multi-mass model MD(2), and the multi-mass model MD(3), while Figure 11(B) illustrates only the multi-mass model MD(3). This graph reveals that the installation of the first TMD 14A, the second TMD 14B, and the third TMD 14C generates anti-resonances HK3A, HK3B, HK3C, and HK3D. The peak frequency of anti-resonance HK3A is 7.125 Hz, the peak frequency of anti-resonance HK3B is 8.375 Hz, the peak frequency of anti-resonance HK3C is 9.875 Hz, and the peak frequency of anti-resonance HK3D is 11.875 Hz.

[0064] In step 4, the natural frequency of the first TMD 14A of the vibration damping device 10 is corrected to 7.125 Hz, which is the peak frequency of anti-resonance HK3A, the natural frequency of the second TMD 14B is corrected to 8.375 Hz, which is the peak frequency of anti-resonance HK3B, the natural frequency of the third TMD 14C is corrected to 9.8756 Hz, which is the peak frequency of anti-resonance HK3C, and the natural frequency of the fourth TMD 14D is set to 11.875 Hz, which is the peak frequency of anti-resonance HK3D (see Figure 7).

[0065] Figure 6(D) shows the multi-mass model MD(4) when it is assumed that the first TMD 14A, whose natural frequency was set to 7.125 Hz in step 4, the second TMD 14B, whose natural frequency was set to 8.375 Hz, the third TMD 14C, whose natural frequency was set to 9.8756 Hz, and the fourth TMD 14D, whose natural frequency was set to 11.875 Hz, are installed on the structural material 52.

[0066] Figures 12(A) and 12(B) are graphs of the resonant frequency characteristics of this multi-mass model MD(4). Note that Figure 12(A) illustrates five models: the single-mass model MD(0), the multi-mass model MD(1), the multi-mass model MD(2), the multi-mass model MD(3), and the multi-mass model MD(4), while Figure 12(B) illustrates only the multi-mass model MD(4). These graphs reveal that anti-resonances HK4A, HK4B, HK4C, and HK4D are generated by installing the first TMD 14A, the second TMD 14B, the third TMD 14C, and the fourth TMD 14D. The peak frequency of anti-resonance HK4A is 6.8 Hz, the peak frequency of anti-resonance HK4B is 7.8 Hz, the peak frequency of anti-resonance HK4C is 9.0 Hz, and the peak frequency of anti-resonance HK4D is 10.5 Hz.

[0067] [How to create a single mass model and a multi-mass model] Next, an example of a method for creating the one mass model MD(0) and the multiple mass models MD(1), MD(2), MD(3), and MD(4) will be described.

[0068] First, as shown in FIG. 13, a three-dimensional model is created using finite element analysis software, taking into consideration the constraint conditions around the slab, which is the structural member 52, and the primary natural frequency and effective mass of the structural member 52 are calculated.

[0069] Then, the calculated primary natural frequency and effective mass are used to create the one-mass model MD(0) shown in Fig. 5(A) above. Specifically, the spring constant k0 is calculated so that the structural material 52 with effective mass m0 has the primary natural frequency of 9.2 Hz, and the one-mass model MD(0) is created.

[0070] 6(A) to 6(D), multi-mass models MD(1), MD(2), MD(3), and MD(4) are created by sequentially adding a first TMD 14A, a second TMD 14B, a third TMD 14C, and a fourth TMD 14D. In this example, the first TMD 14A, the second TMD 14B, the third TMD 14C, and the fourth TMD 14D have the same masses mA, mB, mC, and mD of the mass member 20, 375 kg (see FIG. 7), and the natural frequencies are set by changing the spring constants kA, kB, kC, and kD (see FIG. 5(B)).

[0071] [How to create a graph of the resonance frequency characteristics for each model] Next, an example of a method for creating a graph of the resonance frequency characteristics, which is the relationship between frequency and acceleration in each model, will be described.

[0072] Using structural analysis software or the like, the sweep wave shown in Fig. 14 is input to the single-mass model MD(0) and the multi-mass models MD(1), MD(2), MD(3), and MD(4), and the response acceleration shown in Fig. 15 is calculated. Note that the sweep wave in Fig. 14 is obtained by changing the excitation frequency from 5 Hz to 12 Hz. Then, using structural analysis software or the like, the calculated response acceleration in Fig. 14 is Fourier transformed, in this case a fast Fourier transform, to create the graphs of Figs. 9 to 12.

[0073] [Effect] Next, the operation of this embodiment will be described.

[0074] The vibration damping device 10 is equipped with multiple tuned mass dampers 14 with different natural frequencies, and therefore is able to achieve vibration reduction effects over a wide range of frequencies. From another perspective, the vibration damping device 10 exerts an effective vibration damping effect over a wide frequency range.

[0075] Then, it is assumed that a plurality of tuned mass dampers 14 are installed in order on the object to be damped, and the frequency of the anti-resonance generated by the tuned mass damper 14 assumed to be installed first is corrected and the natural frequency of the tuned mass damper 14 assumed to be installed next is set, thereby suppressing anti-resonance.

[0076] In this embodiment, the graph in Figure 12(B) finally shows the resonance frequency characteristics when the vibration damping device 10 is installed on the structural material 52. Looking at this graph, it can be seen that an effective vibration reduction effect is obtained for vibrations in a wide frequency range other than the primary natural frequency of the structural material 52. It can also be seen that although anti-resonances HK4A, HK4B, HK4C, and HK4D occur, the acceleration is small in all cases and the anti-resonances are suppressed.

[0077] Additionally, multi-mass models MD(1), MD(2), MD(3), and MD(4) are created by sequentially adding tuned mass dampers 14 to the single-mass model MD(0) of structural member 52. Then, sweep waves are input to the multi-mass models MD(1), MD(2), MD(3), and MD(4) to calculate the response acceleration, and the calculated response acceleration is Fourier transformed to find the anti-resonance frequency. Therefore, the anti-resonance frequency achieved by sequentially adding tuned mass dampers 14 can be easily found.

[0078] In this procedure, the natural frequency and effective mass are determined only from the three-dimensional model of the structural material 52, and with the vibration control device 10 installed, the resonant frequency characteristics of the multi-mass models MD(1), MD(2), MD(3), and MD(4) are determined by sequentially adding tuned mass dampers 14 to the one-mass model MD(0) created based on the three-dimensional model.

[0079] Therefore, compared to the case where a three-dimensional model is created and analyzed to determine anti-resonance each time a tuned mass damper 14 is added to the structural material 52, anti-resonance can be easily determined and the natural frequency of the multiple tuned mass dampers 14 that make up the vibration control device 10 can be easily set.

[0080] <Other>

[0081] The present invention is not limited to the above embodiment.

[0082] For example, in the above embodiment, the vibration damping device 10 has a structure in which the four tuned mass dampers 14 are attached to the support base 12 as an integrated unit, but this is not limited to this. The four tuned mass dampers 14 may not be attached to the support base 12 or the like. For example, the four tuned mass dampers 14 may be installed adjacent to the structural member 52.

[0083] Furthermore, for example, in the above embodiment, the vibration damping device 10 has four tuned mass dampers 14, but this is not limited to this. The vibration damping device 10 may have two or more tuned mass dampers 14.

[0084] Furthermore, the structures of the vibration damping device 10 and tuned mass damper 14 in the above-described embodiment are merely examples and are not intended to be limiting. For example, the connecting member 22 of the tuned mass damper 14 has a structure in which the spring element and the damping element are integrally formed, with the elastomer 26 fixed to the entire surface of the metal coil spring 24, but the present invention is not limited to this. A tuned mass damper having a structure in which the spring element and the damping element are provided separately is also possible.

[0085] Furthermore, the present invention can be embodied in various forms without departing from the spirit of the present invention. [Explanation of symbols]

[0086] 10 Vibration control device 14 Tuned Mass Damper 52 Structural materials (examples of vibration control objects)

Claims

1. A method for setting specifications of a vibration control device having a plurality of tuned mass dampers, comprising: Assume that a plurality of the tuned mass dampers are installed in sequence on an object to be damped; First, the natural frequency of the tuned mass damper assumed to be installed is set to the primary natural frequency of the object to be damped, determining the anti-resonance frequency produced by the tuned mass damper(s) assumed to be installed; a step of correcting the natural frequency of one or more of the tuned mass dampers assumed to have been installed first to the anti-resonance frequency determined in the previous step, and setting the natural frequency of the tuned mass damper assumed to be installed next; Repeat, How to set the specifications of a vibration control device.

2. The frequency of the anti-resonance is calculating the primary natural frequency and effective mass of the object to be damped by a finite element method; creating a one-mass model of the object to be damped from the calculated first-order natural frequency and effective mass; a step of adding the tuned mass damper assumed to be installed to the single mass model to create a multi-mass model; a step of inputting a sweep wave into the multi-mass model and calculating a response acceleration; a step of Fourier transforming the calculated response acceleration; To find it, A method for setting specifications of a vibration damping device according to claim 1.

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