JP2010090555A - Natural frequency identification method, structure base-isolating method, and structure vibration-control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a natural frequency identification method in which a natural frequency in a specific vibration mode as a specific vibration mode of a structure is identified through simple procedures. <P>SOLUTION: This natural frequency identification method superseding a conventional natural frequency identification method includes: a step of connecting a mass damper with a spring along the direction of relatively displacing a screw feeding direction, between two points relatively displaced in the specific vibration mode in the specific location of the structure; a step of acquiring vibration data of the mass damper with the spring in accordance with a damper natural frequency ωr of the mass damper with the spring, while changing the damper natural frequency ωr; and a step of determining the natural frequency ωn in the specific vibration mode of the building through the use of the vibration data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a natural frequency identification method for identifying a natural frequency in a specific vibration mode, which is a specific vibration mode of a structure, and a structure isolation that uses the method to isolate a specific vibration mode of the structure. It relates to the method or structural structural vibration control method.

When an earthquake occurs, structures such as buildings and structures are shaken horizontally and vertically.
When the acceleration level due to an earthquake or the like is large, the structure is damaged, or an object in the structure receives an acceleration exceeding an expectation or a displacement exceeding the expectation.
Therefore, a seismic isolation device that reduces the vibration energy transmitted from the foundation to the structure to isolate the vibration, or a vibration suppression that absorbs the vibration energy and reduces the vibration level when the structure vibrates. Devices of various structures have been tried as devices.
By appropriately setting the specifications of the structure and the elements constituting the structure, desired seismic isolation performance and damping performance can be exhibited.

For example, a rotary shaft provided with a linear motion shaft provided with a male screw directed in the screw feed direction along the longitudinal direction, a female screw fitted to the male screw, a frame for rotatably supporting the rotary body, an inner surface of the frame, and a rotary body A viscous mass damper composed of a viscous fluid enclosed in a gap between the two is used.
The viscous mass damper has an apparent inertial mass mr and a linear motion axis that are constant values obtained by dividing the reaction force acting when the linear motion shaft is linearly displaced at a predetermined relative acceleration by the relative acceleration of the linear motion displacement. And a damping coefficient c corresponding to a value obtained by dividing the reaction force acting when the linear displacement is performed at the relative speed by the relative speed.

A viscous mass damper with a spring in which an elastic body is connected in series to the viscous mass damper is used.
The viscous mass damper with a spring has a modulus of elasticity kb, which is a value obtained by dividing the reaction force generated when the spring element is displaced by a relative distance in the linear motion direction, and the linear motion axis of the viscous mass damper in the linear motion direction. The damper natural frequency ωr corresponding to the apparent inertial mass mr, which is the value obtained by dividing the reaction force acting in the linear motion direction by the relative acceleration when linearly moving at a predetermined relative acceleration, and the linear motion of the viscous mass damper It has a damping coefficient C corresponding to a value obtained by dividing the reaction force acting in the linear motion direction by the relative velocity when the shaft is linearly moved at a constant relative velocity.

When the linear motion shaft is linearly displaced, the rotating body rotates.
A rotational reaction force corresponding to the rotational inertia ratio of the rotating body is generated. The rotational reaction force is converted into a reaction force in the direction of linear displacement by the action of the male screw and the female screw.
When the rotating body rotates, a shearing force is generated in the viscous fluid enclosed in the gap between the rotating body and the frame, and a rotational reaction force corresponding to the shearing force is generated. The rotational reaction force is converted into a reaction force in the direction of linear displacement by the action of the male screw and the female screw.
The reaction force due to the inertial force and the shearing force has a dynamic characteristic as a mass system in which an apparent large mass and a large damper are combined as compared with the mass of the rotating body and the amount of the viscous fluid.
Since the viscous mass damper and the elastic body are connected in series, it has vibration characteristics as a spring mass system combined with an apparent large mass and a large damper.

The inventors connect this spring-equipped viscous mass damper to the structure, and if the natural frequency of the structural body and the natural frequency of the viscous mass damper with spring are in an appropriate relationship, the structure can be isolated efficiently. I found out that I can dampen it.
In general, an appropriate relationship between the natural frequency of a structure and the natural frequency of a viscous mass damper with a spring is obtained by numerical analysis on the assumption that the natural frequency of the structure can be identified.
To identify the natural frequency of a structure, conventionally, an acceleration pickup or the like is fixed to the structure and the structure freely vibrates or the structure is forcibly vibrated to analyze the output of the acceleration pickup. From the analysis result, the natural frequency of the structure is identified.

When trying to identify the natural frequency of a steel structure or a reinforced concrete structure, the structure has a large number of vibration modes and a large damping occurs for each vibration mode.
For this reason, it has been difficult to identify the natural frequency with higher accuracy by the conventional identification method of the natural frequency.

Japanese Patent Laid-Open No. 10-100955 JP-A-10-184757 JP 2000-017885 A JP 2003-138784 A JP 2004-239411 A JP 2005-180492 A JP 2005-207547 A

  The present invention has been devised in view of the above-described problems, and a natural frequency identification method for identifying a natural frequency in a specific vibration mode, which is a specific vibration mode of a structure, by a simple procedure and its inherent characteristic. The present invention seeks to provide a structure isolation method that isolates a specific vibration mode of a structure using a frequency identification method or a structural system oscillation method that suppresses vibration.

  In order to achieve the above object, a natural frequency identification method for identifying a natural frequency in a specific vibration mode, which is a specific vibration mode of a structure according to the present invention, is a male screw whose screw feed direction is directed along the longitudinal direction. A mass damper having a linear motion shaft provided with a rotary body provided with a female screw fitted to the male screw, and a frame that rotatably supports the rotary body, and a linear motion displacement displaced along the screw feeding method A preparatory step of preparing a mass damper with a spring having an elastic member that generates an elastic reaction force corresponding to the above and having the mass damper and the elastic member connected in series along the screw feeding direction; A connecting step of connecting the spring-loaded mass damper so that the screw feed direction is along the direction of relative displacement between two points of relative displacement in a specific vibration mode at a specific location of While changing at least one of the inertia ratio or the elastic coefficient of the elastic member to change the damper natural frequency ωr, which is the natural frequency of the mass damper with the spring, the vibration data of the mass damper with the spring is changed to the natural frequency of the damper. A data acquisition step for acquiring data corresponding to ωr and a natural frequency determination step for determining the natural frequency ωn in the specific vibration mode of the building using the vibration data are provided.

With the above-described configuration of the present invention, the mass damper with a spring connects the mass damper and the elastic member in series along the screw feeding direction. The mass damper includes a linear motion shaft provided with a male screw directed in a screw feeding direction along a longitudinal direction, a rotating body provided with a female screw fitted to the male screw, and a frame that rotatably supports the rotating body. Have. The elastic member generates an elastic reaction force corresponding to a linear displacement displaced along the screw feeding method. The spring-loaded mass damper is connected so that the screw feed direction is along the direction of relative displacement between two points where relative displacement is performed in a specific vibration mode at a specific location of the structure. The vibration data of the mass damper with spring is changed while changing the damper natural frequency ωr, which is the natural frequency of the mass damper with spring, by changing at least one of the rotational inertia ratio of the rotating body or the elastic coefficient of the elastic member. Data is acquired in correspondence with the damper natural frequency ωr. The natural frequency ωn in the specific vibration mode of the building is determined using the vibration data.
As a result, vibration data of a specific vibration mode that has an excellent relative displacement between the two points of the structure can be acquired, and the natural frequency of the specific vibration mode of the structure can be accurately identified based on the vibration data. .

  Below, the natural frequency identification method which concerns on embodiment of this invention is demonstrated. The present invention includes any of the embodiments described below, or a combination of two or more of them.

In the natural frequency identification method according to the embodiment of the present invention, the vibration data includes vibration amplitude ΔU in the screw feed direction of the mass damper with the spring and the screw feed of the mass damper or the elastic member. Including the value X corresponding to the amplitude response ratio ΔU ′ / ΔU with the vibration amplitude ΔU ′ in the direction, and the natural frequency determining step corresponds to the maximum value Xmax of which the value is the maximum among the values X A value equal to the frequency ωr is determined to be the natural frequency ωn in the specific vibration mode of the building.
According to the configuration of the embodiment of the present invention, the value X is the vibration amplitude ΔU in the screw feed direction of the mass damper with spring and the vibration amplitude ΔU ′ in the screw feed direction of one of the mass damper or the elastic member. Is a value corresponding to the amplitude response ratio ΔU ′ / ΔU. A value equal to the damper natural frequency ωr corresponding to the maximum value Xmax having the maximum value among the values X is determined as the natural frequency ωn in the specific vibration mode of the building.
As a result, using the phenomenon that the mass damper with spring having the natural frequency ωr of the damper resonates with the vibration of the specific vibration mode in which the relative displacement is excellent between the two points of the structure, the specific vibration of the structure is obtained. The natural frequency ωn in the mode can be accurately identified.

Further, in the natural frequency identification method according to the embodiment of the present invention, the vibration data corresponds to a vibration amplitude ΔU ′ (t) in real time in the screw feed direction of one of the mass damper or the elastic member. The natural frequency of the damper that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the real time value Y (t) in the natural frequency determination step. The natural frequency at the apex of the other peak in the vicinity of the peak having the apex at ωr is determined to be the natural frequency ωn of the building.
With the configuration of the embodiment according to the present invention, the real time value Y (t) corresponds to the vibration amplitude ΔU ′ (t) in the real time in the screw feed direction of one of the mass damper or the elastic member. Is the value to be In the spectrum graph obtained by frequency analysis of the real-time value Y (t), the natural vibration at the peak of another peak near the peak having the peak at the damper natural frequency ωr appearing along the frequency on the horizontal axis. The number is determined to be the natural frequency ωn of the building.
As a result, using the phenomenon that the mass damper with spring having the natural frequency ωr of the damper resonates with the vibration of the specific vibration mode in which the relative displacement is excellent between the two points of the structure, the specific vibration of the structure is obtained. The natural frequency ωn in the mode can be accurately identified.

Further, in the natural frequency identification method according to the embodiment of the present invention, the vibration data corresponds to a vibration amplitude ΔU ′ (t) in real time in the screw feed direction of one of the mass damper or the elastic member. The natural frequency of the damper that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the real time value Y (t) in the natural frequency determination step. It is determined that the natural frequency at the peak apex when the pair of adjacent peaks in the vicinity of ωr move and overlap with each other according to the change of the damper natural frequency ωr is the natural frequency ωn of the building. To do.
With the configuration of the embodiment according to the present invention, the real time value Y (t) corresponds to the vibration amplitude ΔU ′ (t) in the real time in the screw feed direction of one of the mass damper or the elastic member. Is the value to be In the spectrum graph obtained by frequency analysis of the real-time value Y (t), a pair of adjacent peaks in the vicinity of the damper natural frequency ωr appearing along the frequency on the horizontal axis represents the damper natural frequency ωr. It is determined that the natural frequency at the peak apex when the relative movement occurs according to the change and overlaps is the natural frequency ωn of the building.
As a result, using the phenomenon that the mass damper with spring having the natural frequency ωr of the damper resonates with the vibration of the specific vibration mode in which the relative displacement is excellent between the two points of the structure, the specific vibration of the structure is obtained. The natural frequency ωn in the mode can be accurately identified.

Further, in the natural frequency identification method according to the embodiment of the present invention, the vibration data corresponds to a vibration amplitude ΔU ′ (t) in real time in the screw feed direction of one of the mass damper or the elastic member. The natural frequency of the damper that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the real time value Y (t) in the natural frequency determination step. When a pair of adjacent peaks in the vicinity of ωr moves relative to each other according to the change in the damper natural frequency ωr and overlaps, a value equal to the damper natural frequency ωr is the natural frequency ωn of the building. decide.
With the configuration of the embodiment according to the present invention, the real time value Y (t) corresponds to the vibration amplitude ΔU ′ (t) in the real time in the screw feed direction of one of the mass damper or the elastic member. The value to be In the spectrum graph obtained by frequency analysis of the real-time value Y (t), a pair of adjacent peaks in the vicinity of the damper natural frequency ωr appearing along the frequency on the horizontal axis represents the damper natural frequency ωr. A value equal to the natural frequency ωr of the damper when they are moved relative to each other and overlapped with each other is determined as the natural frequency ωn of the building.
As a result, using the phenomenon that the mass damper with spring having the natural frequency ωr of the damper resonates with the vibration of the specific vibration mode in which the relative displacement is excellent between the two points of the structure, the specific vibration of the structure is obtained. The natural frequency ωn in the mode can be accurately identified.

Further, in the natural frequency identification method according to the embodiment of the present invention, the vibration data includes the vibration amplitude ΔU (t) in the screw feed direction of the mass damper with the spring in real time and the mass damper or the elastic member. The real time value Z (t) corresponding to the amplitude response ratio ΔU ′ (t) / ΔU (t) in real time with the vibration amplitude ΔU ′ (t) in real time in one of the screw feeding directions. And the natural frequency at the peak apex that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the real time value Z (t) in the natural frequency determining step is the damper natural frequency. Determine ωr.
With the configuration of the embodiment according to the present invention, the real time value Z (t) is the vibration amplitude ΔU (t) in the screw feed direction of the mass damper with the spring and the mass damper or the elastic member. It is a value corresponding to the amplitude response ratio ΔU ′ (t) / ΔU (t) in real time with the vibration amplitude ΔU ′ (t) in real time in one of the screw feeding directions. In the spectrum graph obtained by frequency analysis of the real time value Z (t), the natural frequency at the peak apex that appears along the frequency on the horizontal axis is determined to be the damper natural frequency ωr.
As a result, the damper natural frequency ωr can be determined by utilizing the phenomenon that the mass damper with a spring having the damper natural frequency ωr is vibrated by the relative displacement that is excellent between the two points of the structure to cause natural vibration. .

  In order to achieve the above object, a structure seismic isolation method for isolating a specific vibration mode of a structure according to the present invention or a structural structural vibration method for damping a structure is characterized by the natural frequency identification method described above. A natural frequency identification step for identifying the frequency ωn and a connection between the two points of the building corresponding to the natural frequency ωn in order to isolate or suppress vibration in a specific vibration mode of the structure. An optimum damper natural frequency derivation step for deriving an optimum damper natural frequency ωropt, which is an optimum value of the damper natural frequency ωr of the mass damper with spring, and a damper natural frequency ωr that matches the value of the optimum damper natural frequency ωropt A damper connecting step of connecting the spring-loaded mass damper between the two points of the structure, and a damper viscosity for enclosing a viscous fluid in the gap between the inner surface of the frame and the rotating body It was intended to comprise a coefficient adjusting step.

According to the configuration of the present invention, the natural frequency ωn of the building is identified by the natural frequency identification method described above. Optimum damper natural frequency ωr of the mass damper with a spring connected between the two points of the building corresponding to the natural frequency ωn in order to isolate or suppress vibrations in a specific vibration mode of the structure The optimum damper natural frequency ωropt, which is a value, is derived. The spring-loaded mass damper having a damper natural frequency ωr that matches the value of the optimal damper natural frequency ωropt is connected between the two points of the structure. A viscous fluid is sealed in a gap between the inner surface of the frame and the rotating body.
As a result, the vibration in the specific vibration mode of the structure can be optimally isolated or controlled.

As described above, the natural frequency identification method according to the present invention has the following effects due to its configuration.
A mass damper with a spring includes a linear motion shaft provided with a male screw directed in a screw feeding direction along a longitudinal direction, a rotating body provided with a female screw fitted to the male screw, and a frame that rotatably supports the rotating body. A mass damper, and an elastic member that generates an elastic reaction force corresponding to a linear displacement that is displaced along the screw feeding method, and the mass damper and the elastic member are moved in the screw feeding direction. Are connected in series.
The spring-loaded mass damper is connected between two points of relative displacement in a specific vibration mode of the structure, and the vibration data of the spring-loaded mass damper is acquired while changing the damper natural frequency of the spring-loaded mass damper. Since the natural frequency ωn in the specific vibration mode of the building is determined from the vibration data, the vibration data of the specific vibration mode that has an excellent relative displacement between the two points of the structure can be acquired, and based on the vibration data The natural frequency of the specific vibration mode can be accurately identified.
Further, it corresponds to the amplitude response ratio ΔU ′ / ΔU between the vibration amplitude ΔU in the screw feed direction of the mass damper with spring and the vibration amplitude ΔU ′ in the screw feed direction of one of the mass damper or the elastic member. Since the value equal to the damper natural frequency ωr corresponding to the maximum value Xmax having the maximum value among the values X is determined to be the natural frequency ωn in the specific vibration mode of the building, the damper natural vibration Using the phenomenon that the mass damper with a spring having a number ωr resonates in a specific vibration mode having an excellent relative displacement between the two points of the structure, the natural frequency ωn in the specific vibration mode of the structure is obtained. Identify accurately.
Further, a spectrum graph obtained by frequency analysis of the real time value Y (t) corresponding to the vibration amplitude ΔU ′ (t) in the real time in the screw feed direction of one of the mass damper and the elastic member. The natural frequency at the top of the other peak in the vicinity of the peak having the peak at the damper natural frequency ωr appearing along the frequency of the horizontal axis is determined to be the natural frequency ωn of the building. Using the phenomenon that the mass damper with a spring having a natural frequency ωr of the resonance resonates with a specific vibration mode having an excellent relative displacement between the two points of the structure, The frequency ωn can be accurately identified.
Further, a spectrum graph obtained by frequency analysis of the real time value Y (t) corresponding to the vibration amplitude ΔU ′ (t) in the real time in the screw feed direction of one of the mass damper and the elastic member. At the peak apex when a pair of adjacent peaks that appear in the vicinity of the damper natural frequency ωr appearing along the frequency on the horizontal axis overlap and move relative to each other according to the change in the damper natural frequency ωr. Since the natural frequency is determined to be the natural frequency ωn of the building, the mass damper with the spring having the damper natural frequency ωr causes a specific relative displacement between the two points of the structure. Using the phenomenon that resonates with the mode, the natural frequency ωn in the specific vibration mode of the structure can be accurately identified.
Further, a spectrum graph obtained by frequency analysis of the real time value Y (t) corresponding to the vibration amplitude ΔU ′ (t) in the real time in the screw feed direction of one of the mass damper and the elastic member. The damper natural frequency when a pair of adjacent peaks in the vicinity of the damper natural frequency ωr appearing along the frequency of the horizontal axis in FIG. 6 moves relative to each other according to the change in the damper natural frequency ωr and overlaps. Is determined to be the natural frequency ωn of the building, so that the mass damper with the spring having the natural frequency ωr of the damper has a specific vibration in which the relative displacement between the two points of the structure is excellent. Using the phenomenon that resonates with the mode, the natural frequency ωn in the specific vibration mode of the structure can be accurately identified.
Further, the vibration amplitude ΔU (t) of the spring-loaded mass damper in the screw feed direction in real time and the vibration amplitude ΔU ′ in the real time of the screw feed direction of one of the mass damper or the elastic member ( t) along the horizontal axis in the spectrum graph obtained by frequency analysis of the real time value Z (t) corresponding to the amplitude response ratio ΔU ′ (t) / ΔU (t) in real time with t) Since the natural frequency at the peak apex is determined to be the damper natural frequency ωr, the mass damper with the spring having the damper natural frequency ωr is vibrated to the structure to cause the natural vibration. Can be used to determine the natural frequency ωr of the damper.

As described above, the structure seismic isolation method or the structural system vibration method according to the present invention has the following effects depending on its configuration.
The natural frequency ωn of the building is identified by the natural frequency identification method described above, and the optimum damper natural frequency ωropt for isolating or damping the structure is derived from the natural frequency ωn. Since the damper natural frequency ωr of the mass damper with spring connected between the two points coincides with the optimal damper natural frequency ωropt, the viscous fluid is sealed in the gap between the inner surface of the frame and the rotating body. , Vibrations in a specific vibration mode of the structure can be optimally isolated or controlled.
Therefore, it is possible to identify the natural frequency in the specific vibration mode of the structure with a simple procedure, and to provide a structure isolation method for isolating the specific vibration mode of the structure or a structural system vibration control method for damping the structure.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

First, the basic structure of a spring-loaded mass damper used in the natural frequency identification method of the present invention will be described with reference to an example.
FIG. 1 is a model diagram of a vibration system according to an embodiment of the present invention. FIG. 2 is a conceptual diagram of a mass damper with a spring according to the first embodiment of the present invention.

The mass damper with a spring is a mechanical element that generates a reaction force in response to a linear displacement, and is configured by connecting the mass damper 100 and the elastic member 200 in series.
The mass damper 100 may further include a viscous fluid.
For example, the viscous mass damper is a mechanical element that generates a reaction force corresponding to a linear motion displacement, and includes a linear motion shaft 110, a rotating body 120, a frame 130, and a viscous fluid 140.
A mass damper having a viscous fluid is referred to as a viscous mass damper.
For example, the viscous mass damper with a spring is connected to the structure 30 using the connecting member 150.
The structure 30 is a structure that is seismically isolated or controlled by a viscous mass damper with a spring.
For seismic isolation, the structural body 30 is provided with a spring-loaded viscous mass damper at the base portion.
For damping, the structure 30 is provided with a spring-loaded viscous mass damper between layers of the main structural members of the structure.

The linear motion shaft 110 is a member provided with a male screw directed in the screw feeding direction along the longitudinal direction.
For example, the linear motion shaft 110 includes a male screw member 111 and a longitudinal member 112.
FIG. 2 shows a male screw member 111 having a male screw formed on the outer periphery and a longitudinal member 112 integrally connected to the male screw member.

The rotating body 120 is a member provided with a female screw that fits into the male screw.
The rotating body 120 includes a disk-shaped rotating member 122 provided with a female screw that fits into the male screw.
For example, the rotating body 120 includes a female screw member 121, a cylindrical rotating member 122, and a rotating shaft 126.
The female screw member 121 is a member provided with a female screw.
The cylindrical rotating member 122 rotates around the central axis corresponding to the linear motion of the linear motion shaft 110.
The female screw member 121 and the disc-shaped rotating member 122 are arranged coaxially.
The rotating shaft 126 is a member that connects the female screw member 121 and the cylindrical rotating member 122.
FIG. 2 shows a rotating body 120 that includes a female screw member 121 provided with a female screw, a rotating member 122, and a rotating shaft 126, and the rotating shaft 126 supports the end of the rotating member 122.
The male screw of the male screw member 111 and the female screw of the female screw member 121 may be combined in a screw shape via a plurality of balls.
When the linear motion shaft 110 is constrained to rotate and linearly moves, the female screw member 121 is rotated via the ball, and the rotary member 122 and the rotary shaft 126 that are coaxially fixed to the female screw member 121 rotate.

The frame 130 is a structure that rotatably supports the rotating body 120.
FIG. 2 shows a frame 130 having a cylindrical structure that surrounds the rotating body 120.
A bearing 135 fixed to the frame 130 rotatably supports the rotating body 120.
The bearing 135 is a mechanical element that rotatably supports the rotating body 120.

The viscous fluid 140 is a liquid sealed in a gap between the inner surface of the frame 130 and the rotating body 120.
When the rotating body 120 rotates relative to the frame 130, the viscous fluid 140 applies a viscous force in the direction opposite to the rotation direction to the rotating body.
The viscous force gives a rotational torque reaction force to the rotating body 120.
The rotational torque reaction force is converted into a reaction force acting in the direction of linear displacement by the action of the male screw and the female screw.
This reaction force is approximately proportional to the speed of the linear displacement of the linear motion shaft.

The connecting member 150 is a member for connecting the spring-loaded mass damper to the structure 30.
The connecting member 150 includes a first connecting member 151 and a second connecting member 152.
The first connecting member 151 is a connecting member that can swing around one movable shaft that intersects the direction of linear displacement.
The first connecting member 151 connects the structural body 30 and the frame 130.
The second connecting member 152 is a connecting member that can swing around one movable shaft that intersects the direction of linear displacement.
The second connecting member 152 connects the linear motion shaft 110 and the elastic member 200.

The elastic member 200 is a member that generates an elastic reaction force corresponding to the linear displacement.
The elastic member 200 includes an elastic plate 211, a first flange 212, and a second flange 213.
The elastic plate 211 is a plate material made of an elastic material.
The elastic plate 211 is sandwiched between the first flange 212 and the second flange 213 with the plate surface along the direction of linear displacement.
When the first flange 212 and the second flange 213 approach and separate along the screw feed direction, a shearing force is generated in the elastic plate 211, and a relative reaction force is generated between the first flange 212 and the second flange 213. This reaction force is approximately proportional to the relative displacement between the first flange 212 and the second flange 213.
The first flange 212 is coupled to the second connecting member 152.
The second flange 213 is coupled to the structure 30.

The damper natural frequency ωr, which is the natural frequency of the mass damper with spring and the viscous mass damper with spring, will be described below with reference to the vibration model.
FIG. 1 shows a vibration model.
The vibration model includes a viscous mass damper system 10, a spring element 20, and a structure 30.
The viscous mass damper system 10 includes an inertia connecting element 11 and a damper element 12.
The structure 30 includes a main mass 31 and a main elastic element 32.
The main mass 31 is an apparent mass when the specific vibration mode of the structure 30 is imitated by a one-degree-of-freedom spring-mass system.
The main elastic element 32 is an apparent elastic element when the specific vibration mode of the structure 30 is imitated by a one-degree-of-freedom spring-mass system.
The damper natural frequency ωr of the viscous mass damper with spring or the mass damper with spring corresponds to the elastic coefficient Kb and the apparent inertia mass mr of the inertia connecting element 11.
The inertia connecting element 11 corresponds to a mechanical element constituted by the linear motion shaft 110, the rotating body 120, and the frame 130.
The elastic coefficient kb is a value obtained by dividing the reaction force generated when the spring element 20 is displaced by the relative distance in the linear motion direction by the relative distance.
The apparent inertial mass mr is a value obtained by dividing the reaction force acting in the linear motion direction by the relative acceleration when the linear motion shaft 110 of the mass damper is linearly moved in the linear motion direction at a predetermined relative acceleration.
Further, the damping coefficient C of the spring-equipped viscous mass damper corresponds to a value obtained by dividing the reaction force acting in the linear motion direction when the linear motion shaft of the viscous mass damper is linearly moved at a constant relative speed, divided by the relative speed.
The damper element 12 of the viscous mass damper with a spring corresponds to a mechanical element constituted by the linear motion shaft 110, the rotating body 120, the frame 130, and the viscous fluid 140.

Below, the attachment structure of several types of mass dampers with a spring to the structure 30 is demonstrated based on figures.
FIG. 3 is an explanatory view of a mounting structure of a mass damper with a spring according to the embodiment of the present invention.
Hereinafter, a plurality of types of mounting structures will be described with reference to the drawings.
The attachment positions in FIG. 3 are exemplary.
The actual attachment position will be described in the description of the natural frequency identification method described later.

First, a first type of mounting structure will be described with reference to the drawings.
A first type of mounting structure is shown at the base of FIG.
FIG. 4 is a detailed explanatory view of the first mounting structure of the mass damper with a spring according to the embodiment of the present invention.
A spring-loaded mass damper is attached to the foundation of the structure 30.
One end of the mass damper with spring is fixed to the foundation, and the other end is fixed to the lower part of the structure.
The screw feeding method of the spring-loaded mass damper is set along the horizontal direction.
If it does in this way, a mass damper with a spring will expand and contract in response to the relative displacement by the vibration mode which carries out relative displacement in the horizontal direction of the foundation of a structure.
When the spring-loaded mass damper expands and contracts, the mass damper 100 and the elastic member 200 expand and contract in each direction along the screw feed direction according to the frequency of vibration.
The sum of the separation distance U1 along the horizontal direction between the attachment points of the mass damper 100 and the separation distance U2 along the horizontal direction between the attachment points of the elastic member 200 is the horizontal between the attachment points of the mass damper with the spring. It corresponds to the separation distance U along the direction.

Next, a second type of mounting structure will be described with reference to the drawings.
A second type of mounting structure is shown in the first floor portion of FIG.
A mass damper with a spring is attached between the layers of the structure 30.
One end of the spring-loaded mass damper is fixed to the lower layer, and the other end is fixed to the upper layer of the structure.
The screw feeding method of the spring-loaded mass damper is set along the vertical direction.
In this way, the mass damper with the spring expands and contracts in response to the relative displacement due to the vibration mode of the vertical stretching vibration with the base of the structure as the supporting point and the upper layer portion as the free end.
When the spring-loaded mass damper expands and contracts, the mass damper 100 and the elastic member 200 expand and contract individually along the screw feed direction according to the frequency of vibration.
The sum of the separation distance U1 along the vertical direction between the attachment points of the mass damper 100 and the separation distance U2 along the vertical direction between the attachment points of the elastic member 200 is vertical between the attachment points of the mass damper with the spring. It corresponds to the separation distance U along the direction.

Next, a third type mounting structure will be described with reference to the drawings.
A third type of mounting structure is shown in the second floor portion of FIG.
FIG. 5 is a detailed explanatory view of a second mounting structure of the mass damper with a spring according to the embodiment of the present invention.
A mass damper with a spring is attached between the layers of the structure 30.
One end of the spring-loaded mass damper is fixed to the lower layer, and the other end is fixed to the upper layer of the structure.
The screw feeding method of the mass damper with the spring is set in the diagonal direction.
In this way, for example, the mass damper with a spring expands and contracts in response to the relative displacement due to the vibration mode of the bending vibration of the cantilever beam having the base of the structure as the supporting point and the upper layer portion as the free end.
When the spring-loaded mass damper expands and contracts, the mass damper 100 and the elastic member 200 expand and contract individually along the screw feed direction according to the frequency of vibration.
The sum of the separation distance U1 along the oblique direction between the attachment points of the mass damper 100 and the separation distance U2 along the oblique direction between the attachment points of the elastic member 200 is the diagonal between the attachment points of the mass damper with the spring. It corresponds to the separation distance U along the direction.

Next, a fourth type mounting structure will be described with reference to the drawings.
A fourth type of mounting structure is shown in the third floor portion of FIG.
A mass damper with a spring is attached between the layers of the structure 30.
One end of the mass damper with the spring is fixed to the lower layer, and the other end is fixed to the structural jig fixed to the upper layer of the structure.
The screw feeding method of the spring-loaded mass damper is set along the horizontal direction.
In this way, for example, the mass damper with a spring expands and contracts in response to the relative displacement due to the vibration mode of the bending vibration of the cantilever beam having the base of the structure as the supporting point and the upper layer portion as the free end.
When the spring-loaded mass damper expands and contracts, the mass damper 100 and the elastic member 200 expand and contract in each direction along the screw feed direction according to the frequency of vibration.
The sum of the separation distance U1 along the horizontal direction between the attachment points of the mass damper 100 and the separation distance U2 along the horizontal direction between the attachment points of the elastic member 200 is the horizontal between the attachment points of the mass damper with the spring. It corresponds to the separation distance U along the direction.

Next, a fifth type mounting structure will be described with reference to the drawings.
A fifth type of mounting structure is shown in the fourth floor portion of FIG.
FIG. 6 is a detailed explanatory view of a third mounting structure of the mass damper with a spring according to the embodiment of the present invention.
A mass damper with a spring is attached between the layers of the structure 30.
One end of the spring-loaded mass damper is fixed to the lower layer, and the other end is fixed to the upper layer of the structure.
The elastic member 200 is an elastic plate 211 having one end fixed to the upper layer and the other end lowered to a free end.
The screw feeding method of the spring-loaded mass damper is set along the horizontal direction.
In this way, for example, the mass damper with a spring expands and contracts in response to the relative displacement due to the vibration mode of the bending vibration of the cantilever beam having the base of the structure as the supporting point and the upper layer portion as the free end.
When the spring-loaded mass damper expands and contracts, the mass damper 100 and the elastic member 200 expand and contract individually along the screw feed direction according to the frequency of vibration.
The sum of the separation distance U1 along the horizontal direction between the attachment points of the mass damper 100 and the separation distance U2 along the horizontal direction of the connection point between the free end of the elastic plate 211 and the mass damper 100 is the spring-equipped mass damper. It corresponds to the separation distance U along the horizontal direction between the attachment points.

Next, a sixth type mounting structure will be described with reference to the drawings.
A sixth type of mounting structure is shown in the fifth floor portion of FIG.
A mass damper with a spring is attached between the layers of the structure 30.
The central part of the mass damper with the spring is fixed to the upper layer, and both ends are fixed to the structural jig fixed to the lower layer of the structure.
The screw feeding method of the spring-loaded mass damper is set along the horizontal direction.
In this way, for example, the mass damper with a spring expands and contracts in response to the relative displacement due to the vibration mode of the bending vibration of the cantilever beam having the base of the structure as the supporting point and the upper layer portion as the free end.
When the spring-loaded mass damper expands and contracts, the mass damper 100 and the elastic member 200 expand and contract individually along the screw feed direction according to the frequency of vibration.
The sum of the separation distance U1 along the horizontal direction between the attachment points of the mass damper 100 and the separation distance U2 along the horizontal direction between the attachment points of the elastic member 200 is the horizontal between the attachment points of the mass damper with the spring. It corresponds to the separation distance U along the direction.

Since the vibration energy that can be stored in the spring-loaded mass damper is usually very small compared to the vibration energy that can be stored in the structure, the spring-loaded mass damper is substantially displaced by the fluctuation of the separation distance U due to the vibration of the structure. It is thought to be subjected to forced vibration.
The expansion / contraction displacement of the separation distance U (t) due to expansion / contraction is defined as ΔU (t). Let the vibration amplitude of the expansion / contraction displacement be ΔU.
The expansion / contraction displacement of the separation distance U1 (t) due to expansion / contraction is assumed to be ΔU1 (t). The vibration amplitude of the expansion / contraction displacement is assumed to be ΔU1.
The expansion / contraction displacement of the separation distance U2 (t) due to expansion / contraction is represented by ΔU2 (t). The vibration amplitude of the expansion / contraction displacement is assumed to be ΔU2.

  Next, a plurality of types of spring-loaded mass dampers having a structure capable of easily changing at least one of the rotational inertia performance ratio of the rotating body of the spring-loaded mass damper or the elastic coefficient of the elastic member will be described based on the drawings. To do.

  First, a mass damper with a spring having a structure capable of easily changing the elastic coefficient of an elastic member of the mass damper with a spring will be described with reference to the drawings.

Three types of elastic members having the laminated elastic plate 214 and capable of easily changing the elastic coefficient will be described.
FIG. 7 is a partial conceptual view of a mass damper with a spring according to the first embodiment of the present invention.
FIG. 7A shows a laminated member 200 that includes a plurality of laminated elastic plates 214 and can change the number of laminated elastic plates 214.
The elastic modulus changes in response to changing the number of layers.
FIG. 7B shows an elastic member having a laminated elastic plate 214 composed of a laminated elastic plate main body 215 provided with a through hole and a laminated elastic plate piece 216 that can be inserted into or removed from the through hole. It is.
Corresponding to the insertion or removal of the laminated elastic plate piece 216 from the through hole, the elastic modulus changes.
FIG. 7C shows an elastic member having a laminated elastic plate 214 made of laminated elastic plate members 127 which are concentrically or spirally stacked and attached or detached freely.
Corresponding to attaching or removing the laminated elastic plate member 127, the elastic coefficient changes.

Hereinafter, two types of elastic members 200 that are configured by the elastic beams 220 and can easily change the elastic coefficient will be described.
FIG. 8 is a conceptual diagram of a mass damper with a spring according to the second embodiment of the present invention.
FIG. 8A shows the elastic beam 220 that can move and fix the attachment position of the mass damper and the elastic beam 220 in a direction crossing the screw feed direction.
For example, the elastic beam 220 includes a fixed leaf spring 221, a first guide member 222, and a second guide member 223. The first guide member 222 can guide and fix the second guide member 223 movably in a direction crossing the screw feeding direction.
The mass damper 100 is fixed to the second guide member 223.
When the second guide member 223 is guided by the first guide member 222 and moved and fixed, the elastic coefficient changes corresponding to the fixed position.

FIG. 8B shows an elastic beam 220 that can change the bending stiffness.
For example, the elastic beam 220 includes a fixed leaf spring 221 and an additional leaf spring 224.
The additional leaf spring 224 can be attached to or removed from the stationary leaf spring 221.
The elastic coefficient changes corresponding to attachment to or removal from the fixed leaf spring 221.

  Next, a mass damper with a spring having a structure capable of easily changing the rotational inertia ratio of the rotating body of the mass damper with a spring will be described with reference to the drawings.

Two types of rotating bodies 120 that are constituted by at least the rotating member 122 of the additional member 123 or the moving member 124 and can easily change the overall rotational inertia ratio will be described.
FIG. 9 is a conceptual diagram of a mass damper with a spring according to the third embodiment of the present invention.
FIG. 9A shows a structure that includes a rotating member 122 and an additional member 123 that is attached to the side surface of the rotating member 122 or is detachably fixed.
For example, the additional member 123 can be attached to or detached from the side surface of the rotating member 122 with the rotation axis aligned.
The rotational inertia ratio of the rotating body 120 changes in accordance with the attachment or removal of the additional member 123.

FIG. 9B shows a structure including a rotating member 122 and a moving member 124 that is fixed to the side surface of the rotating member 122 so as to be movable along the radial direction.
For example, the moving member 124 is guided by the guide member 125 extending along the radial direction on the side surface of the rotating member 122 and fixed so as to be movable in the radial direction.
Corresponding to the movement of the moving member 124 in the radial direction, the rotational inertia ratio of the rotating body 120 changes.

Next, two types of rotating bodies 120 in which the additional member 129 is coaxially attached to the rotating member 122 and the overall rotational inertia ratio can be changed by changing the additional member 129 will be described.
FIG. 10 is a conceptual diagram of a mass damper with a spring according to the fourth embodiment of the present invention.
FIG. 10A shows a structure in which the additional member 123 is attached to the rotating shaft 126 of the rotating body 120 or is detachably fixed.
For example, the end surface of the rotating shaft 126 protrudes from the frame 130, and the additional member 123 is coaxially attached to or detached from the end surface of the rotating shaft 126.
As the additional member 123 is attached to or detached from the end surface of the rotating shaft 126, the rotational inertia ratio of the rotating body 120 changes.
Further, the rotational inertia ratio of the rotating body 120 changes corresponding to the additional member 123 having a different size being attached to the end surface of the rotating shaft 126.

FIG. 10B shows a structure composed of a rotating member 122 and a moving member 128 that is guided by the rotating member 122 and fixed so as to be movable in the radial direction.
For example, the rotating shaft 126 supports the rotating member 122, and the moving member 128 guided by the groove provided in the rotating member 122 is fixed so as to be movable in the radial direction.
For example, a plurality of moving members 128 are guided by the additional member 123 and fixed so as to be movable in the radial direction.
Corresponding to the movement of the moving member 128 in the radial direction, the rotational inertia ratio of the rotating body 120 changes.

Next, a structure in which the outer peripheral end portion of the rotating member 122 protrudes from the frame 130 and the moving member 128 or the additional member 129 is supported on the outer peripheral portion of the rotating member 122 will be described.
FIG. 11A shows a structure including a rotating member 122 and a moving member 128 fixed to the rotating member 122 so as to be movable in the radial direction.
For example, the frame 130 includes a first side plate member 131 and a second side plate member 132, and the seal member 139 is provided between the first side plate member 131 and the rotating member 122 and between the second side plate member 132 and the rotating member 122. Seal.
The moving member 128 is guided and fixed in a groove provided in the rotating member 122 so as to be movable in the radial direction.
For example, a plurality of moving members 128 are guided and fixed in a plurality of grooves provided in the rotating member 122 so as to be movable in the radial direction.
Corresponding to the movement of the moving member 128 in the radial direction, the rotational inertia ratio of the rotating body 120 changes.

FIG. 11B shows a structure including a rotating member 122 and an additional member 129 that is attached to the edge of the rotating member 122 or is detachably fixed.
For example, the frame 130 includes a first side plate member 131 and a second side plate member 132, and the seal member 139 is provided between the first side plate member 131 and the rotating member 122 and between the second side plate member 132 and the rotating member 122. Seal.
For example, the additional member 129 is attached to the edge of the rotating member 122 or is detachably attached.
For example, the plurality of additional members 129 are attached to a plurality of circumferential locations on the edge of the rotating member 122 or are detachably attached.
Corresponding to the addition or removal of the additional member 129, the rotational inertia ratio of the rotating body 120 changes.

  Next, the natural frequency identification method and the structure seismic isolation method or the structural regime vibration method according to the embodiment of the present invention will be described.

First, the natural frequency identification method will be described.
The natural frequency identification method is a method for identifying a natural frequency in a specific vibration mode that is a specific vibration mode of a structure, and includes a preparation step S11, a connection step S12, a data acquisition step S13, and a natural frequency determination step. And S14.

The preparation step S11 is a step of preparing a mass damper with a spring.
The mass damper with a spring is obtained by connecting a mass damper and an elastic member in series along the screw feeding direction.
The mass damper includes a linear motion shaft 110 provided with a male screw directed in a screw feeding direction along the longitudinal direction, a rotating body 120 provided with a female screw fitted to the male screw, and a frame 130 that rotatably supports the rotating body. I have it.
The elastic member 200 generates an elastic reaction force corresponding to a linear displacement that is displaced along a screw feeding method.

The spring-loaded mass damper may further include a viscous fluid 140.
The viscous fluid is a fluid sealed in a gap between the inner surface of the frame and the rotating body.
Whether or not the viscous fluid is provided is determined by the degree of vibration of the spring-loaded mass damper in the subsequent process.
In addition, the amount of viscous fluid is determined by the degree of vibration of the mass damper with a spring in a subsequent process.
If there is a problem because the vibration of the mass damper with spring in the subsequent process is large, the amount of viscous fluid is increased.
If there is a problem because the vibration of the mass damper with spring in the subsequent process is small, the viscous fluid is not sealed.
In addition, if the inconvenience occurs because the vibration of the mass damper with spring in the subsequent process is small, the amount of viscous fluid is reduced.

  In order to facilitate the work in the post-process, a mass damper with a spring having the above-described structure may be used.

The connecting step S12 is a step of connecting a mass damper with a spring so that the screw feed direction is along the direction of relative displacement between two points that undergo relative displacement in a specific vibration mode at a specific location of the structure.
First, a specific vibration mode is determined.
Further, the vibration order may be determined.
The vibration mode specifies the type of vibration of the structure.
The vibration mode depends on the structure of the structure.
For example, when the structure is a substantially tower-like building, vibration modes such as a bending vibration mode, a torsional vibration mode, a pitching vibration mode, and a horizontal shear deformation mode are generally considered.
For example, when the structure is a shell-like structure, generally, a vibration mode accompanied by out-of-plane deformation of a surface member constituting the shell is considered.
Two points that are relatively displaced in a specific vibration mode at a specific location of the structure are determined.
In order to facilitate post-processing, two points are determined at specific locations of the structure where an excellent relative displacement is expected in a specific vibration mode.
A mass damper with a spring is connected so that the screw feed direction is along the direction of relative displacement between the two determined points.
In this way, when vibration energy is input to the structure, the forcible displacement for forcibly oscillating the mass damper with spring is increased, and the S / N ratio of vibration data acquired in a subsequent process is improved.
For example, when the linear motion shaft 110 of the mass damper with spring and the elastic member 200 are connected, the frame 130 of the mass damper with spring is connected to one of the two points, and the elastic member 200 is Connect to the other of the two.
For example, when the linear motion shaft 110 of the mass damper with spring and the elastic member 200 are connected via the second connecting member 152, the frame 130 of the mass damper with spring is set to one of the two points. It connects via the connection member 151 and connects the elastic member 200 to the other of two points.

In the data acquisition step S13, at least one of the rotational inertia ratio of the rotating body 120 or the elastic coefficient of the elastic member 200 is changed to change the damper natural frequency ωr, which is the natural frequency of the spring-loaded mass damper, and the mass damper with spring. This is a step of acquiring data corresponding to the vibration data of the damper corresponding to the natural frequency ωr of the damper.
For example, by changing the rotational inertia ratio of the rotating body 120 and changing the damper natural frequency ωr, which is the natural frequency of the spring-loaded mass damper, between a small value and a large value continuously or intermittently, The damper vibration data is acquired in correspondence with the damper natural frequency ωr.
For example, the mass damper with the spring is changed while changing the elastic coefficient of the elastic member 200 so that the natural frequency ωr of the damper, which is the natural frequency of the mass damper with the spring, is continuously or intermittently changed between a small value and a large value. Is acquired in correspondence with the damper natural frequency ωr.

The vibration data may include the value X.
The value X is a value corresponding to the amplitude response ratio ΔU ′ / ΔU between the vibration amplitude ΔU in the screw feed direction of the mass damper with spring and the vibration amplitude ΔU ′ in one screw feed direction of the mass damper or the elastic member. .
For example, the vibration amplitude ΔU is the vibration amplitude of the separation distance U in the screw feed direction at two points where a mass damper with a spring is attached.
For example, the vibration amplitude ΔU ′ is the vibration amplitude of the separation distance U1 in the screw feeding direction between both ends for attaching the elastic member 200.
For example, the vibration amplitude ΔU ′ is the vibration amplitude of the separation distance U2 in the screw feed direction at both ends for mounting the mass damper 100.

Further, the vibration data may include a real-time value Y (t).
The real time value Y (t) is a real time value corresponding to the vibration amplitude ΔU ′ (t) in the real time in the screw feed direction of one of the mass damper and the elastic member.
Here, “in real time” means “obtained continuously with the passage of actual time”.
For example, the vibration amplitude ΔU ′ (t) is a real-time vibration amplitude of the separation distance U1 in the screw feed direction between the both ends for attaching the elastic member 200.
For example, the vibration amplitude ΔU ′ (t) is the real-time vibration amplitude of the separation distance U2 in the screw feed direction at both ends for mounting the mass damper 100.

Further, the vibration data may include a real time value Z (t).
The real time value Z (t) is the vibration amplitude ΔU (t) in the screw feed direction of the mass damper with a spring in real time and the vibration amplitude in the real time of one of the mass dampers or the elastic member in the screw feed direction. It is a value corresponding to the amplitude response ratio ΔU ′ (t) / ΔU (t) in real time with ΔU ′ (t).
For example, the amplitude response ratio ΔU ′ (t) / ΔU (t) is the vibration amplitude ΔU (t) in the screw feed direction of the mass damper with spring in real time and screw feed at both ends for attaching the elastic member 300. It is the ratio in real time to the vibration amplitude ΔU1 (t) in real time in the direction.
For example, the amplitude response ratio ΔU ′ (t) / ΔU (t) is the vibration amplitude ΔU (t) in the screw feed direction of the mass damper with a spring and the screw feed at both ends for attaching the mass damper 100. It is the ratio in real time to the vibration amplitude ΔU2 (t) in real time in the direction.

The natural frequency determination step S14 is a step of determining the natural frequency ωn in the specific vibration mode of the building using the vibration data.
Hereinafter, a plurality of types of natural frequency determination steps in the natural frequency identification method according to the embodiment of the present invention will be described with reference to the drawings.

First, the first type of natural frequency determination step will be described.
FIG. 13 is an explanatory diagram of the natural frequency identification method according to the first embodiment of the present invention.
In the first type of natural frequency determination step, a value equal to the damper natural frequency ωr corresponding to the maximum value Xmax of the values X is the natural frequency ωn in the specific vibration mode of the building. And decide.
FIG. 13 is a graph showing the results of a numerical simulation performed assuming a vibration model of a structure and a vibration model of a mass damper with a spring.
In the numerical simulation, actual seismic data was input to the vibration model of the structure.
In the graph, the horizontal axis represents the ratio ωr / ωn between the damper natural frequency ωr and the natural frequency ωn in the specific vibration mode of the structure.
The vertical axis is the value X.
The solid line in the graph is the value X that matches ΔU1 / ΔU. This corresponds to a value X corresponding to ΔU1 / ΔU.
A two-dot broken line in the graph is a value X that matches ΔU2 / ΔU. This corresponds to a value X corresponding to ΔU2 / ΔU.
From the graph, the value X takes the maximum value when ωr / ωn = 1.
That is, it can be seen that the natural frequency ωn in the specific vibration mode of the structure is equal to the damper natural frequency ωr corresponding to the maximum value Xmax having the maximum value among the values X.

Next, the second to fourth types of natural frequency determination steps of the present invention will be described with reference to the drawings.
FIG. 14 is an explanatory diagram of case 1 of the natural frequency identification method according to the second embodiment of the present invention. FIG. 15 is an explanatory diagram of case 2 of the natural frequency identification method according to the second embodiment of the present invention. FIG. 16 is an explanatory diagram of case 3 of the natural frequency identification method according to the second embodiment of the present invention. FIG. 17 is an explanatory diagram of case 4 of the natural frequency identification method according to the second embodiment of the present invention.

FIG. 14, FIG. 15, FIG. 16, and FIG. 17 are graphs of the results of numerical simulation performed assuming a vibration model of a structure and a vibration model of a mass damper with a spring.
In the numerical simulation, actual seismic data was input to the vibration model of the structure.
(A) in FIG. 14, FIG. 15, FIG. 16, and FIG. 17 is a Fourier spectrum graph of ΔU, ΔU1, and ΔU2 when the damper natural frequency ωr is changed stepwise in the numerical simulation.
(B) in FIGS. 14, 15, 16, and 17 are Fourier spectrum graphs of ΔU1 / ΔU and ΔU2 / ΔU when the damper natural frequency ωr is changed stepwise in the numerical simulation.

The damper natural frequency was assumed to be four cases.
In case 1, ωr is equal to 0.5ωn.
In case 2, ωr is equal to ωn.
In case 3, ωr is equal to 1.41ωn.
In case 4, ωr is equal to 3.16 ωn.
FIG. 14 shows a numerical simulation result in case1.
FIG. 15 shows a numerical simulation result in case2.
FIG. 16 shows a numerical simulation result in case3.
FIG. 17 shows a numerical simulation result in case4.

Below, the 2nd type natural frequency determination process is demonstrated.
In the second type of natural frequency determination step, in the spectrum graph obtained by frequency analysis of the real-time value Y (t), the vicinity of the peak having a vertex at the damper natural frequency ωr appearing along the frequency on the horizontal axis. It is determined that the natural frequency at the top of the other peak at is the natural frequency ωn of the building.
14 (A) to 15 (A) show the peaks of the Fourier spectrum graph shown in (A) even if the damper natural frequency ωr changes near the peak having the peak at the damper natural frequency ωr. It shows that there is another peak whose position does not change, and the peak of the other peak is the natural frequency ωn in the specific vibration mode of the building.

In the second type of natural frequency determination step, the natural frequency at the peak apex that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the value Z (t) is determined as the damper natural frequency. You may determine that it is (omega) r.
That is, it is assumed that the peak that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the value Z (t) is the resonance peak of the mass damper with spring.
14 (B) to 15 (B), in the Fourier spectrum graph shown in (B), there is a peak where the position of the apex changes when ωr changes, and the apex of the peak is the damper natural frequency ωr. It is shown that.

Next, a third type of natural frequency determination step will be described.
In the third type of natural frequency determination step, 1 adjacent to the damper natural frequency ωr appearing along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the real-time value Y (t). It is determined that the natural frequency at the peak apex when the peak of the pair is relatively moved and overlapped according to the change of the damper natural frequency ωr is the natural frequency ωn of the building.
14A to 15A show a pair of peaks adjacent to each other in the vicinity of the damper natural frequency ωr according to the change in the damper natural frequency ωr in the Fourier spectrum graph shown in FIG. It is shown that the peak apex when they are moved relative to each other and overlap is the natural frequency ωn in the specific vibration mode of the building.
FIG. 14, FIG. 16 and FIG. 17 (A) show that adjacent peaks are a peak where the position of the apex changes as the damper natural frequency ωr changes and the position of the apex where the damper natural frequency ωr changes. Indicates that the peak does not change.
FIG. 15A shows that when the damper natural frequency ωr matches the natural frequency ωn in the specific vibration mode of the structure, a pair of peaks overlap.

In the third type of natural frequency determination step, the natural frequency at the peak apex that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the value Z (t) is determined as the damper natural frequency. You may determine that it is (omega) r. That is, it is assumed that the peak that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the value Z (t) is the resonance peak of the mass damper with spring.
Since this estimation process is the same as that in the second type natural frequency determination process, description thereof is omitted.

Next, a fourth type natural frequency determination step will be described.
The fourth type natural frequency determination step S14 includes a pair of adjacent natural frequencies ωr that appear along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the value Y (t). A value equal to the damper natural frequency ωr when the peak overlaps due to relative movement according to the change of the damper natural frequency ωr is determined as the natural frequency ωn of the building.
Since description of FIGS. 14-17 is the same as the thing of the 3rd type natural frequency determination process, description is abbreviate | omitted.

In the fourth type of natural frequency determination step, the natural frequency at the peak apex that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the value Z (t) is determined as the damper natural frequency. You may determine that it is (omega) r. That is, it is assumed that the peak that appears along the frequency on the horizontal axis in the spectrum graph obtained by frequency analysis of the value Z (t) is the resonance peak of the mass damper with spring.
Since this estimation process is the same as that in the second type natural frequency determination process, description thereof is omitted.

Next, a structure seismic isolation method or a structural system vibration method according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 12 is a procedure diagram of the natural frequency identification method and the structure seismic isolation method or the structural regime vibration method according to the embodiment of the present invention.
The structure seismic isolation method or the structural system vibration method is a structural base isolation method that isolates a specific vibration mode of the structure or a structural system vibration method that suppresses vibration.
The structure seismic isolation method or the structural system vibration method includes a natural frequency identification step S10, an optimum damper natural frequency derivation step S20, a damper connection step S30, and a damper viscosity coefficient adjustment step S40.

  The natural frequency identification step S10 is a step of identifying the natural frequency ωn of the building by the above-described natural frequency identification method.

In the optimum damper natural frequency deriving step S20, a mass damper with a spring connected between two points of the building corresponding to the natural frequency ωn in order to isolate or suppress vibration in the specific vibration mode of the structure. This is a step of deriving an optimum damper natural frequency ωropt which is an optimum value of the damper natural frequency ωr.
For example, assuming a numerical model in which a mass damper with a spring is connected to a structure having a natural frequency ωn in a specific vibration mode, the response magnification of the structure is calculated when the structure is vibrated, and the excitation frequency ω When the ratio ω / ωn between the natural frequency and the natural frequency ωn is the horizontal axis, and the response magnification of the structure is the vertical axis, the value is constant regardless of the value of the viscosity coefficient due to the viscous fluid on the line indicating the response magnification. The ratio of the damper natural frequency ωr to the damper natural frequency so that the response magnifications at a plurality of fixed points become substantially equal is determined, and the damper natural frequency satisfying the ratio is set as the optimum damper natural frequency ωropt.
Here, the response magnification is the absolute response magnification, which is the ratio of the static displacement of the structure due to the excitation force when the structure is forced to vibrate and the amplitude of the structure that vibrates in response. Object that vibrates in response to displacement response magnification, which is the ratio of the displacement of the support when vibrating and the displacement of the structure that vibrates in response, or the acceleration of the support when the support is forced There is an acceleration response magnification, which is a ratio to the acceleration of.

The damper connection step S30 is a step of connecting a mass damper with a spring having a damper natural frequency ωr that matches the value of the proper damper natural frequency ωropt between two points of the structure.
For example, a mass damper with a spring having the above-described structure and capable of easily changing at least one of the rotational inertia ratio of the rotating body or the elastic coefficient of the elastic member is connected to the structure, and the damper natural frequency ωr is set to the optimum damper specific characteristic. A value equal to the frequency ωropt is set.
For example, a mass damper with a spring having a new structure that matches the damper natural frequency ωr with a value equal to the optimum damper natural frequency ωropt is assembled and connected between two points of the structure.

The damper viscosity coefficient adjusting step S22 is a step of sealing the viscous fluid in the gap between the inner surface of the frame and the rotating body.
For example, two fixed points located on a line indicating the response magnification when the ratio ω / ωn between the excitation frequency ω and the natural frequency ωn is taken as the horizontal axis and the response magnification of the structure is taken as the vertical axis by numerical analysis. The optimum damping coefficient at which the response magnification at is substantially maximum is obtained, and the viscous fluid is sealed in the gap between the inner surface of the frame and the rotating body so that the damping coefficient becomes the optimum damping coefficient.
Viscous fluid is sealed in the gap between the inner surface of the frame and the rotating body so that the response magnification of the structure becomes a desired value.

As described above, the natural frequency identification method according to the present invention has the following effects due to its configuration.
A mass damper with a spring includes a linear motion shaft provided with a male screw directed in a screw feed direction along a longitudinal direction, a rotating body provided with a female screw fitted to the male screw, and a frame that rotatably supports the rotating body. A mass damper and an elastic member that generates an elastic reaction force corresponding to a linear displacement displaced along a screw feeding method, and the mass damper and the elastic member are connected in series along the screw feeding direction. Is.
A mass damper with a spring is connected between two points of relative displacement in a specific vibration mode of the structure, and vibration data of the mass damper with a spring is obtained while changing the damper natural frequency ωr of the mass damper with the spring. Since the natural frequency ωn in the specific vibration mode of the building is determined from the data, vibration data of the specific vibration mode with excellent relative displacement between the two points of the structure can be acquired, and the specific vibration mode of the specific vibration mode can be acquired based on the vibration data. The natural frequency can be identified accurately.
That is, the mass damper with a spring selectively inputs vibration in the screw feed direction between two points of the structure and responds to vibration, so that the S / N ratio of vibration data is remarkably improved.
Further, among the values X corresponding to the amplitude response ratio ΔU ′ / ΔU between the vibration amplitude ΔU in the screw feed direction of the mass damper with spring and the vibration amplitude ΔU ′ in one screw feed direction of the mass damper or the elastic member. Since the value equal to the damper natural frequency ωr corresponding to the maximum value Xmax having the maximum value is determined as the natural frequency ωn in the specific vibration mode of the building, the spring having the damper natural frequency ωr The natural frequency ωn in the specific vibration mode of the structure can be accurately identified by utilizing the phenomenon that the attached mass damper resonates with the specific vibration mode in which the relative displacement between the two points of the structure is excellent.
In the spectrum graph obtained by frequency analysis of the real time value Y (t) corresponding to the real time vibration amplitude ΔU ′ (t) in the screw feed direction of one of the mass damper and the elastic member, the horizontal axis The natural frequency at the top of the other peak in the vicinity of the peak having the peak at the damper natural frequency ωr appearing along the frequency is determined to be the natural frequency ωn of the building. Using the phenomenon that a mass damper with a spring having a number ωr resonates with a specific vibration mode that has an excellent relative displacement between two points of the structure, the natural frequency ωn in the specific vibration mode of the structure is accurately determined. Can be identified.
In the spectrum graph obtained by frequency analysis of the real time value Y (t) corresponding to the real time vibration amplitude ΔU ′ (t) in the screw feed direction of one of the mass damper and the elastic member, the horizontal axis The natural frequency at the peak apex when a pair of adjacent peaks in the vicinity of the damper natural frequency ωr appearing along the frequency of each other moves relative to each other according to the change in the damper natural frequency ωr and overlaps. Since the natural frequency ωn of the damper is determined, the mass damper with a spring having the natural frequency ωr of the damper resonates with a specific vibration mode that has an excellent relative displacement between two points of the structure. Thus, the natural frequency ωn in the specific vibration mode of the structure can be accurately identified.
In the spectrum graph obtained by frequency analysis of the real time value Y (t) corresponding to the real time vibration amplitude ΔU ′ (t) in the screw feed direction of one of the mass damper and the elastic member, the horizontal axis A pair of adjacent peaks in the vicinity of the damper natural frequency ωr appearing along the frequency of the relative frequency moves relative to the damper natural frequency ωr and overlaps with the damper natural frequency ωr to obtain a value equal to the damper natural frequency. Since the natural frequency is determined to be ωn, the mass damper with spring having the natural frequency ωr of the damper resonates with a specific vibration mode that has an excellent relative displacement between two points of the structure. Thus, the natural frequency ωn in the specific vibration mode of the structure can be accurately identified.
Also, the actual vibration amplitude ΔU (t) in the screw feed direction of the mass damper with the spring and the real time vibration amplitude ΔU ′ (t) in the screw feed direction of one of the mass damper or the elastic member. In the spectrum graph obtained by frequency analysis of the real time value Z (t) corresponding to the amplitude response ratio ΔU ′ (t) / ΔU (t) in time, the peak at the apex of the peak appearing along the frequency on the horizontal axis. Since the natural frequency is determined to be the damper natural frequency ωr, the mass damper with spring having the damper natural frequency ωr resonates with a specific vibration mode that has an excellent relative displacement between two points of the structure. By utilizing this phenomenon, the damper natural frequency ωr can be determined.

Further, as described above, the structure seismic isolation method or the structural system vibration method according to the present invention has the following effects depending on its configuration.
The natural frequency ωn of the building is identified by the natural frequency identification method described above, and the optimum damper natural frequency ωropt for isolating or damping the structure is derived from the natural frequency ωn. Since the damper natural frequency ωr of the spring-loaded mass damper connected between the two points is adjusted to be the optimal damper natural frequency ωropt, the viscous fluid is sealed in the gap between the inner surface of the frame and the rotating body. It is possible to optimally isolate or control the vibration of the structure in a specific vibration mode.

The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.
Although various structures of the mass damper with a spring were demonstrated, it is not limited to this.

It is a model diagram of a vibration system according to an embodiment of the present invention. It is a conceptual diagram of the mass damper with a spring which concerns on 1st embodiment of this invention. It is explanatory drawing of the attachment structure of the mass damper with a spring which concerns on embodiment of this invention. It is detail explanatory drawing of the 1st attachment structure of the mass damper with a spring which concerns on embodiment of this invention. It is detail explanatory drawing of the 2nd attachment structure of the mass damper with a spring which concerns on embodiment of this invention. It is detail explanatory drawing of the 3rd attachment structure of the mass damper with a spring which concerns on embodiment of this invention. It is a partial conceptual diagram of the viscous mass damper with a spring which concerns on 1st embodiment of this invention. It is a conceptual diagram of the mass damper with a spring which concerns on 2nd embodiment of this invention. It is a conceptual diagram of the mass damper with a spring which concerns on 3rd embodiment of this invention. It is a conceptual diagram of the mass damper with a spring which concerns on 4th embodiment of this invention. It is a conceptual diagram of the mass damper with a spring which concerns on 5th embodiment of this invention. It is a procedure figure of the natural frequency identification method and structure seismic isolation method or structural system vibration method which concern on embodiment of this invention. It is explanatory drawing of the natural frequency identification method which concerns on 1st embodiment of this invention. It is explanatory drawing of case1 of the natural frequency identification method which concerns on 2nd embodiment of this invention. It is explanatory drawing of case2 of the natural frequency identification method which concerns on 2nd embodiment of this invention. It is explanatory drawing of case3 of the natural frequency identification method which concerns on 2nd embodiment of this invention. It is explanatory drawing of case4 of the natural frequency identification method which concerns on 2nd embodiment of this invention.

Explanation of symbols

S10 Natural frequency identification step S11 Preparatory step S12 Connection step S13 Data acquisition step S14 Natural frequency determination step S20 Optimal damper natural frequency derivation step S30 Damper connection step S40 Damper viscosity coefficient adjustment step 10 Viscous mass damper system 11 Inertial connection element 12 Damper element 20 Spring element 30 Structure 31 Main mass 32 Main elastic element 40 Support structure 50 Mounting structure 100 Mass damper 110 Linear motion shaft 111 Male screw member 120 Rotating body 121 Female screw member 122 Rotating member 123 Additional member 124 Moving member 125 Guide member 126 Rotating shaft 128 Moving member 129 Additional member 130 Frame 131 First side plate member 132 Second side plate member 135 Bearing 139 Seal member 140 Viscous fluid 150 Connection member 151 First connection member 152 Second connection portion 153 Third connecting member 154 Fourth connecting member 200 Elastic member 211 Elastic plate 212 First flange 213 Second flange 214 Laminated elastic plate 215 Laminated elastic plate body 216 Laminated elastic plate fragment 217 Laminated elastic plate member 220 Elastic beam 221 Fixed leaf spring 222 First guide member 223 Second guide member 224 Additional leaf spring

Claims (7)

A natural frequency identification method for identifying a natural frequency in a specific vibration mode which is a specific vibration mode of a structure,
A mass damper having a linear motion shaft provided with a male screw directed in a screw feeding direction along a longitudinal direction, a rotating body provided with a female screw fitted to the male screw, and a frame that rotatably supports the rotating body; A spring having an elastic member that generates an elastic reaction force corresponding to a linear displacement displaced along the screw feeding method, and the mass damper and the elastic member are connected in series along the screw feeding direction. A preparation process to prepare a mass damper with
A connecting step of connecting the mass damper with a spring so as to follow the direction of relative displacement of the screw feed direction between two points of relative displacement in a specific vibration mode at a specific position of the structure;
The vibration data of the mass damper with spring is changed while changing the damper natural frequency ωr, which is the natural frequency of the mass damper with spring, by changing at least one of the rotational inertia ratio of the rotating body or the elastic coefficient of the elastic member. A data acquisition step of acquiring data corresponding to the damper natural frequency ωr;
A natural frequency determination step of determining the natural frequency ωn in the specific vibration mode of the building using the vibration data;
A natural frequency identification method comprising: The vibration data is an amplitude response ratio ΔU ′ / ΔU between the vibration amplitude ΔU in the screw feed direction of the mass damper with spring and the vibration amplitude ΔU ′ in the screw feed direction of one of the mass damper or the elastic member. Contains the corresponding value X,
The natural frequency determining step determines that a value equal to the damper natural frequency ωr corresponding to the maximum value Xmax having the maximum value among the values X is the natural frequency ωn in the specific vibration mode of the building. ,
The natural frequency identification method according to claim 1, wherein: The vibration data includes a real time value Y (t) corresponding to a vibration amplitude ΔU ′ (t) in real time in the screw feed direction of one of the mass damper or the elastic member,
In the spectrum graph obtained by frequency analysis of the real-time value Y (t) in the natural frequency determination step, there is another peak in the vicinity of a peak having an apex at the damper natural frequency ωr that appears along the frequency on the horizontal axis. Determining the natural frequency at the peak apex to be the natural frequency ωn of the building,
The natural frequency identification method according to claim 1, wherein: The vibration data includes a real time value Y (t) corresponding to a vibration amplitude ΔU ′ (t) in real time in the screw feed direction of one of the mass damper or the elastic member,
In the spectrum graph obtained by frequency analysis of the real time value Y (t) in the natural frequency determination step, a pair of adjacent peaks appearing along the horizontal frequency in the vicinity of the damper natural frequency ωr. Determining that the natural frequency at the peak apex when the dampers move relative to each other according to the change of the damper natural frequency ωr is the natural frequency ωn of the building;
The natural frequency identification method according to claim 1, wherein: The vibration data includes a real time value Y (t) corresponding to a vibration amplitude ΔU ′ (t) in real time in the screw feed direction of one of the mass damper or the elastic member,
In the spectrum graph obtained by frequency analysis of the real time value Y (t) in the natural frequency determination step, a pair of adjacent peaks appearing along the horizontal frequency in the vicinity of the damper natural frequency ωr. A value equal to the damper natural frequency ωr when they are moved relative to each other according to the change in the damper natural frequency ωr and overlapped is determined as the natural frequency ωn of the building;
The natural frequency identification method according to claim 1, wherein: The vibration data includes vibration amplitude ΔU (t) of the spring-loaded mass damper in the screw feed direction in real time and vibration amplitude ΔU of the mass damper or one of the elastic members in the screw feed direction in real time. A real time value Z (t) corresponding to the amplitude response ratio ΔU '(t) / ΔU (t) in real time with'(t);
In the spectrum graph obtained by frequency analysis of the real time value Z (t) in the natural frequency determination step, the natural frequency at the peak apex that appears along the frequency on the horizontal axis is the damper natural frequency ωr. To decide,
6. The natural frequency identification method according to claim 3, wherein the natural frequency is identified. A structure seismic isolation method that isolates a specific vibration mode of a structure or a structural system vibration control method that suppresses vibration,
A natural frequency identification step of identifying the natural frequency ωn of the building by one of the natural frequency identification methods according to claim 1;
Optimum damper natural frequency ωr of the mass damper with a spring connected between the two points of the building corresponding to the natural frequency ωn in order to isolate or suppress vibrations in a specific vibration mode of the structure An optimum damper natural frequency derivation step for deriving the optimum damper natural frequency ωropt, which is a value;
A damper connecting step of connecting the spring-loaded mass damper having the damper natural frequency ωr substantially equal to the value of the optimum damper natural frequency ωropt between the two points of the structure;
A damper viscosity coefficient adjusting step of sealing a viscous fluid in a gap between the inner surface of the frame and the rotating body;
A structure seismic isolation method or a structural system vibration method characterized by comprising:

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