JP4788134B2 - Damping structure of structure - Google Patents

Description

  The present invention connects a plurality of structures such as buildings and towers having the same or close vibration characteristics at places having different vibration amplitudes, and utilizes the interaction force between the structures, The present invention relates to a vibration control structure for controlling vibration.

Japanese Patent Laid-Open No. 7-190136

  Currently, the number of buildings is increasing. However, the higher the building height, the lower the building rigidity and the lower the natural frequency. For this reason, vibration is likely to occur due to disturbance such as wind. These vibrations cause deterioration of habitability and damage to the building. The Great Hanshin-Awaji Earthquake caused devastating destruction of 10-story buildings and high-rise buildings even if they were not destroyed. Therefore, vibration control is necessary to solve this problem. Therefore, many studies on vibration control methods for high-rise buildings have been made. In particular, an active mass damper (hereinafter abbreviated as AMD) system using the inertial force of a weight is well known. However, this method is effective against small and medium level disturbances such as wind, but it is difficult to obtain a large damping force and cannot cope with a large earthquake. Furthermore, since the natural frequency of the building decreases as the building becomes even higher, the AMD system that uses inertial force as the control force cannot provide sufficient control force, and even the vibration caused by wind cannot be controlled. is there.

  The vibration control method proposed to solve these problems is the coupled vibration control method. This is because a structure such as a building is connected to the structure with a vibration damping device such as a damper or an actuator, and the mutual action / reaction force is used as a control force, and vibrations between the structures such as the building can be detected. This is a control method. Compared with the AMD method, this method can obtain a large control force, and since the control force does not depend on the frequency, it can cope with not only the vibration of the skyscraper but also a large earthquake. In this method, three high-rise buildings (Triton Towers) constructed in Triton Square in the Harumi Redevelopment Area are connected by two vibration control devices called active bridges to control the vibration of these high-rise buildings due to wind. Has already been put to practical use.

  However, in the proposed coupled vibration control method, it is impossible to control buildings with the same height and the same natural frequency, and when the natural frequency of the connected structure approaches, The damping effect is reduced. There is also a request to control a plurality of buildings having the same height by the above method, but it is difficult to adopt this method because the natural frequency of the building approaches. In addition, since the coupled vibration control method is a method of controlling by utilizing the mutual reaction force of a plurality of buildings and structures, there is an essential problem that it cannot be adopted for an independent building or structure.

  As described above, the conventional AMD method can be applied only to the control of building winds and small earthquakes, and it is difficult to apply the AMD method to a high-rise building exceeding 500 meters. Therefore, a joint vibration control method was proposed, but this method is a method of controlling vibration by connecting buildings and buildings or tower structures with vibration control devices, and their natural frequencies are different. It is effective in the case. However, when the natural frequencies of buildings and tower structures are equal, no action / reaction force can be obtained and vibration control cannot be performed. Even if the natural frequencies are different, the effect of the vibration control is small when they are close to each other.

  In addition, when the building or tower structure is standing independently, in order to apply the above-mentioned connected vibration control method, the building or tower structure is constructed separately for the outer tower and the inner tower, and both are controlled. In this case, there will be a large difference in rigidity between the outer tower and the inner tower, so the inner tower will shake greatly in order to control the outer tower with high rigidity. There is also a problem that the outer tower cannot be controlled.

  The present invention has been made in view of the above, and the object of the present invention is to effectively control the vibration of structures having the same or close natural frequencies, and of course the vibration caused by the wind is large. An object of the present invention is to provide a vibration control structure that can cope with an earthquake and that can be easily designed optimally.

  The vibration control structure of a plurality of structures according to the present invention connects at least a pair of structures having the same or close natural frequencies via connecting means at portions having different vibration amplitudes, and the pair of structures are mutually connected. The vibration of the pair of structures is controlled by the acting force.

  In the present invention, the pair of structures are connected by the connecting means at portions having different vibration amplitudes, and the vibration of the pair of structures is controlled by the interaction force between the pair of structures. Therefore, as a result of obtaining a large interaction force, it is possible to effectively control the vibration of the structure, and it is possible to cope with large earthquakes as well as shaking due to wind.

  The present invention relates to a symmetrical structure, a pair of structures having the same height or the same or close vibration characteristics, a plurality of middle, high, and skyscraper structures having the same height, and for example, space. It can be applied to structures such as solar cell paddles for stations and piping systems placed in parallel, and can be widely applied from vibrations of general flexible structures due to wind to vibration suppression due to large earthquakes. Even if the heights of the structures are not the same, if the natural frequency is close, it is possible to obtain a large damping performance that cannot be obtained by the conventional coupled damping system.

  Further, the structure damping structure of the present invention divides one structure to form at least a pair of divided structures, and connects the divided pairs of divided structures with portions having different vibration amplitudes. And the vibration of the pair of divided structures is controlled by the interaction force between the pair of divided structures.

  According to such a vibration control structure, since the vibration of the pair of divided structures is controlled by the interaction force between the pair of divided structures, one building or the like is divided. Even if it is a structure, as a result of obtaining a large interaction force, it is possible to effectively control the vibration of the structure, and it is possible to provide a structure that is resistant to large earthquakes as well as shaking due to wind.

  In the present invention, the connecting means preferably has a vibration damping device and an elastic device. In this case, the vibration damping device and the elastic device may be arranged in series.

  Preferred examples of the vibration damping device include a hydraulic damper, a magnetic damper, a friction damper, a viscous damper, a viscoelastic damper, and the like, and a more preferable example is a magnetic damper using a permanent magnet or the like. . Preferred examples of the elastic device include a coil spring and a cantilever beam.

  In the present invention, a wide range of vibration problems can be addressed by selecting a damping device according to the vibration level to be subjected to vibration control. For example, an active vibration control device is suitable for controlling the vibration of a high-rise building due to wind. In addition, an active vibration control device is uneconomical for a large earthquake, and a damper that does not consume energy, a small variable damping damper, or the like may be selected. In the present invention, since an optimum design method is obtained when a damper is used for the vibration damping device, a large earthquake can be effectively dealt with by using it. Furthermore, it is possible to cope with a large earthquake by combining the connecting means with passive devices such as oil dampers and active devices.

  Further, in the vibration damping structure of the present invention, the spring rigidity and the damping coefficient of the coupling means can be divided by the coupling portion so that the optimum vibration damping can be obtained in any of the above damping structures. It is determined on the basis of an equivalent model of the vibration control structure obtained when represented by the two mass point model.

  In the present invention, when each of a pair of structures connected via a pair of connecting means is expressed by a two-mass model divided by connecting portions, each is a simple equivalent model (dynamic vibration absorber type model). If this equivalent model is used, for example, when a cantilever structure and a damper are used as the connecting means, the cantilever structure is represented by a spring. The values of the spring stiffness and the damping coefficient of the damper can be determined from the viewpoint that the vibration can be most effectively suppressed, and thus the optimum design can be easily performed.

  In the present invention, the connecting means may have the vibration damping device and the elastic device as described above, but has both functions of the vibration damping device and the elastic device, for example, a damping function and an elastic function. A damping spring device having the following may be provided.

  It is possible to effectively control the vibrations of structures with the same or close natural frequency to each other, and can cope with large earthquakes as well as vibration due to wind, and can be easily designed optimally. A damping structure can be provided.

  Hereinafter, embodiments of the present invention will be described in more detail based on examples shown in the drawings. The present invention is not limited to these examples.

  The vibration damping structure 1 shown in FIG. 1 oscillates a pair of structures having the same or close natural frequency and the same vibration characteristics, in this example, buildings 2 and 3, which are tower-like structures. The parts 4, 5, 6 and 7 having different amplitudes are connected via a pair of connecting means 8 and 9, and the vibrations of the buildings 2 and 3 are controlled by the interaction force between the buildings 2 and 3. is there.

  Each of the buildings 2 and 3 is constructed on a foundation 10, and the connecting means 8 includes a cantilever 11 as an elastic device fixed to a portion 4 which is the upper end of the building 2 at one end, and a cantilever at one end. 11 and a damper 13 as a vibration control device connected to a free end 12 which is a lower end of 11 and a portion 5 below the upper end of the building 3 at the other end. 11 is elastically swingable in the substantially horizontal direction on the free end 12 side with the part 4 as a fulcrum, and the damper 13 is expandable and contractable in the substantially horizontal direction, and the vibration in the substantially horizontal direction. The vibration is attenuated during expansion and contraction.

  The connecting means 9 is connected to a cantilever 15 as an elastic device fixed to a portion 6 which is the upper end of the building 3 at one end, and a free end 16 which is a lower end of the cantilever 15 at one end. It has a damper 17 as a vibration control device connected to a portion 7 below the upper end of the building 2 at the end, and the cantilever 15 is also a fulcrum at the portion 6 like the cantilever 11. The damper 17 is elastically swingable in the substantially horizontal direction on the free end 16 side, and, like the damper 13, the damper 17 is extendable in the substantially horizontal direction and the vibration in the substantially horizontal direction is expanded and contracted. The vibration is damped.

  In order to confirm the operation analysis and effects of the vibration damping structure 1 shown in FIG. 1 having a symmetric structure including the connecting means 8 and 9, a model vibration damping structure A as shown in FIG. It was created. In the model damping structure A, 2A corresponds to the building 2, 3A corresponds to the building 3, 11A corresponds to the cantilever 11, 13A corresponds to the damper 13, 15A corresponds to the cantilever 15, and 17A corresponds to the damper 17. The building model 2A corresponding to the building 2 is, as shown in FIG. 3A, two aluminum flat plates 21 having a height of 1000 [mm], a width of 150 [mm], and a thickness of 2 [mm]. And two acrylic plates 22 having a length of 150 [mm], a width of 80 [mm], and a thickness of 25 [mm], and a two-layer structure for attaching the damper model 13A. Up to 30 mm is completely fixed. 3B and 3C, the vibration mode shapes of the primary mode (4.16 Hz) and the secondary mode (11.14 Hz) obtained by the mode analysis of the building model 2A are shown by solid lines. A building model 3A corresponding to the building 3 is also formed in the same manner as the building model 2A.

In this analysis, the control target mode is set to a primary mode and a secondary mode, and the order is reduced to a two-degree-of-freedom system using a reduced-order physical model creation method. The primary mode is identified on the top floor, and the secondary mode is identified on the middle floor. FIG. 4 shows a schematic diagram and physical parameters of a two-degree-of-freedom system in the building model 2A. Here, m ₁ is the mass of the upper floor in each of the building models 2A and 3A, and 0.6379 (kg), m ₂ is the mass of the lower floor in each of the building models 2A and 3A, 0.8893 (kg), k ₁₀ is the overall spring stiffness of each of the building models 2A and 3A, and −140.65 (N / m), k ₁₂ is above each of the building models 2A and 3A. The spring stiffness of the floor, 1513 (N / m), k ₂₀ is the spring stiffness of the lower upper floor of each of the building models 2A and 3A, and is 1539 (N / m).

FIG. 5 shows the model damping structure A when the cantilever models 11A and 15A are represented as springs and are connected to each other by such cantilever models 11A and 15A and damper models 13A and 17A arranged in series. M ₁₁ is the mass of the upper floor in the building model 2A, m ₁₂ is the mass of the lower floor in the building model 2A, k ₁₁₀ is the spring rigidity of the entire building model 2A, and k ₁₁₂ is the upper mass of the building model 2A. The spring stiffness of the floor, k ₁₂₀ is the spring stiffness of the upper floor of the building model 2A, m ₂₁ is the mass of the upper floor of the building model 3A, m ₂₂ is the mass of the lower floor of the building model 3A, and k ₂₁₀ is The spring rigidity of the entire building model 3A, k ₂₁₂ is the spring rigidity of the upper floor of the building model 3A, k ₂₂₀ is the spring rigidity of the lower upper floor of the building model 3A, and k is the spring rigidity of each of the cantilever models 11A and 15A. Spring stiffness, C is the damping coefficient of each of the damper models 13A and 17A. Here, in the model damping structure A, since the pair of building models 2A and 3A having the same vibration characteristics are arranged in parallel, the left and right two-degree-of-freedom system models have the same physical parameters. The feature of this model is that cantilever models 11A and 15A (spring elements) and damper models 13A and 17A (damping elements) are arranged in series. Further, since the connected models are symmetrical, they can be expressed as a simple equivalent model as shown in FIG. 6 when the ground (base 10) is vibrated. Since this is nothing but a dynamic vibration absorber type model, parameters for optimum design can be derived with reference to the optimum design method of the dynamic vibration absorber.

  In this invention, the fixed point theory currently used for the design of a dynamic vibration damper is applied to the optimal design method of the damping structure 1. FIG. According to FIG. 6, the frequency response curve of the displacement x1 of the mass point 1 with respect to the displacement u of the foundation 10 is as shown in FIG. A one-dot chain line is a response when the attenuation coefficient c is zero, and a dotted line is a response when the attenuation coefficient c is infinite. There are three intersections (indicated by small circles) in this frequency response. Even if the attenuation changes, the frequency response curve passes through this intersection point, so this is called a fixed point. Therefore, the optimum design of the connecting means 8 and 9 can be obtained by obtaining the conditions for creating a response curve that maximizes the fixed point. The design procedure is as follows.

1. Draw a frequency response curve when the damping coefficient c is zero and when it is infinite, change the value of the spring stiffness k, and among the three intersections (fixed points), the height of the low frequency fixed point for the primary mode is low The value of the spring stiffness k is determined as follows.
2. An attenuation coefficient c having a maximum frequency response curve is determined at a low frequency fixed point.

By the above procedure, the optimum spring stiffness k _opt = 2800 [N / m] and the optimum damping coefficient c _opt = 33 [Ns / m].

  A frequency response curve calculated using these optimum values is shown by a solid line in FIG. It is the vibration of the primary mode that leads to the destruction of the building in the event of a large earthquake. Since the resonance peak of this primary mode is well suppressed and the peak value passes through a fixed point, the connecting means 8 and 9 The spring stiffness k and the damping coefficient c are optimally designed. FIG. 8 shows the impulse response of the mass point 1 due to the vibration of the ground at the time. It can be seen that the vibrations of the building models 2A and 3A are quickly damped. This is simultaneously attenuated by the pair of building models 2A and 3A.

The effects of the present invention are shown by experimentally confirming the simulation results obtained as described above. Based on the optimally designed spring stiffness k _opt and damping coefficient c _opt , cantilever models 11A and 15A and damper models 13A and 17A related to the connecting means 8 and 9 were created.

The cantilever models 11A and 15A are made of aluminum having a thickness of 6 [mm] × a length of 550 [mm] × a width of 50 [mm], and the thickness was determined from a theoretical formula using an optimal spring stiffness k _opt . The damper is a magnetic damper using a copper plate and a magnet, and is designed using a theoretical formula so as to have an optimum attenuation coefficient c _opt .

  From the frequency response of FIG. 9, each resonance peak is well reduced as in the simulation. In the impulse response of FIG. 10 as well, the vibration converges quickly about 3 [sec] from the occurrence of the vibration, and the effect of the present invention is shown.

As described above, in the damping structure 1, the spring stiffness k and the damping coefficient c of the connecting means 8 or 9 are divided into the two mass points m shown in FIG. 5 in which the pair of buildings 2 and 3 are separated by the connecting portions 5 and 7, respectively. It is determined on the basis of the equivalent model of the vibration control structure 1 shown in FIG. 6 obtained by the ₁₁ and m ₁₂ and m ₂₁ and m ₂₂ models, so that optimum vibration damping is obtained.

  In another example of the vibration damping structure 1 shown in FIGS. 11 and 12, the cantilever 11 of the connecting means 8 is fixed to the portion 4 which is the top of the building 2, and the free end 12 of the vibration damping device is attached to the free end 12. An inner cylinder 31 is attached, and one end of the outer cylinder 32 of the vibration damping device is firmly fixed to the middle part 5 of the building 3 and the other end of the outer cylinder 32 is attached to the building 2. The middle cylinder 31 is supported by the slide mechanism 33 so as to be movable in the horizontal direction. The inner cylinder 31 can be smoothly moved in the axial direction by the guide 34 inside the outer cylinder 32. 32 is connected by a damper 35 such as one or a plurality of hydraulic dampers. Although not shown, the connecting means 9 side is configured in the same manner.

  As described above, the vibration damping structure 1 shown in FIGS. 11 and 12 also includes the vibration damping device including the inner cylinder 31, the outer cylinder 32, the slide mechanism 33, the guide 34, and the damper 35 and the elastic structure including the cantilever 11. Buildings 2 and 3 are connected by parts 4 and 5 having different vibration amplitudes via connecting means 8 having a device, and parts 2 and 3 having different vibration amplitudes are connected by similar connecting means 9. 6 and 7, and thus the vibration of the buildings 2 and 3 is controlled by the interaction force between the buildings 2 and 3.

  In the example of the damping structure 1 shown in FIGS. 11 and 12, the passive damper 35 is used as a damping device for damping. Instead, a semi-active damping device or an active damping device is used. It is also possible to use a hybrid damper that combines a passive damper and an active damper. When the vibrator is activated, it can cope with any vibration disturbance. In the example shown in FIGS. 11 and 12, if a passage is provided in the inner cylinder 31, it can function as an evacuation route in an emergency such as a fire.

  Moreover, you may comprise the damping structure 1 by arrange | positioning the connection means 8 and 9 upside down. That is, as shown in FIG. 13, one end of the cantilever 11 is fixed to the part 5, the free end 12 is connected to one end of the damper 13, and the other end of the damper 13 is connected to the part 4. One end of 15 may be fixed to the part 7, the free end 16 may be connected to one end of the damper 17, and the other end of the damper 17 may be connected to the part 6.

  Furthermore, you may comprise the damping structure 1 using one connection means among a pair of connection means 8 and 9, for example, as shown in FIG. In this case, a certain level of vibration damping effect can be obtained, although not as much as the optimum attenuation described above.

  Furthermore, the present invention can also be applied to a pair of buildings, a single building, or a general structure in parallel. For example, as shown in FIG. 15, if a building 40 is divided into four to form divided buildings 41, and these divided buildings 41 are connected by connecting means 8 and / or 9 to form a vibration control structure 42, one building will be formed. In spite of this building 40, a high-rise building that is strong against large earthquakes and strong winds can be realized. Further, according to the vibration control structure 42 of FIG. 15, it is possible to realize a vibration control structure that can endure in all directions even if wind or an earthquake strikes from any direction.

It is a perspective explanatory view of a preferred embodiment according to the present invention. It is explanatory drawing of the building model structure for confirming the vibration damping effect of the example shown in FIG. It is explanatory drawing of the building model structure and vibration mode form of the example shown in FIG. 2, Comprising: (a) is explanatory drawing of a building model structure, (b) is explanatory drawing of a primary vibration mode, (c) is two. It is explanatory drawing of a next vibration mode. It is explanatory drawing of a 2-degree-of-freedom system model and a physical parameter. It is explanatory drawing of the connected 2 degree-of-freedom system model and a physical parameter. FIG. 6 is an explanatory diagram of an equivalent model of the two-degree-of-freedom system model shown in FIG. 5. It is a frequency response curve figure of the mass point 1. FIG. It is an impulse response curve diagram. It is the frequency response curve figure obtained by experiment. It is the impulse response curve figure obtained by experiment. It is front explanatory drawing of another preferable Example by this invention. It is a partially expanded explanatory view of the example shown in FIG. It is front explanatory drawing of the further another Example preferable by this invention. It is front explanatory drawing of the further another Example preferable by this invention. It is front explanatory drawing of the further another Example preferable by this invention.

Explanation of symbols

1 Damping structure 2, 3 Building 4, 5, 6, 7 Site 8, 9 Connecting means

Claims (1)

By dividing one of the structure forms at least a pair of split structure, the divided pair of divided structures are connected via a pair of connecting means on different parts component of the vibration amplitude, a pair of divided structure A vibration damping structure for a structure in which vibration of the pair of divided structures is controlled by an interaction force between objects , wherein one of the pair of connecting means is a pair of divided structures at one end. One cantilever as one elastic device fixed to one split structure of the object, and one end connected to the free end of one cantilever and the other split structure at the other end One damper as one damping device connected to the other, and one cantilever is elastically shaken in a substantially horizontal direction on the free end side with one divided structure as a fulcrum. One damper is placed in a substantially horizontal direction. In addition, the vibration can be attenuated in the substantially horizontal vibration expansion and contraction, and the other of the pair of connection means is connected to the other of the pair of divided structures at one end The other cantilever as the other elastic device fixed to the split structure, and one end connected to the free end of the other cantilever and the other end connected to the one split structure The other damper as the other vibration damping device, and the other cantilever is elastically swingable in a substantially horizontal direction on the free end side with the other divided structure as a fulcrum. The other damper is a structure for damping the structure which is extendable in a substantially horizontal direction and is adapted to attenuate the vibration in the vibration extension / contraction in the substantially horizontal direction .

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