JP3246373B2 - Structure damping method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a non-linear dynamic vibration absorber having a weight as an additional mass and a spring as a constituent element at the top or inside of a structure, so that the structure can withstand a disturbance such as an earthquake or wind. Seismic how the structure for reducing the response
It relates to.

[0002]

2. Description of the Related Art Conventionally, as a passive type vibration damping device, a weight is placed on the top or inside of a structure, and it is supported by a spring and a damper to synchronize with the natural period of the structure. There is a dynamic vibration absorber that reduces the vibration of a structure (for example, Japanese Patent Publication No. 3-38386, Japanese Patent Publication No. 5-5574).
No. 1).

Further, as a passive type vibration damping device using a damping device, a damping coefficient of a damping device arranged in a form connected to a seismic element in a column-beam frame of a structure is set to a certain value, or Set to change automatically according to the state,
There is one that aims to reduce vibration of a building (for example, Japanese Patent No. 25
No. 13356, Japanese Patent No. 2528589, etc.).

On the other hand, as an active control type vibration damping system, the applicant installs a seismic element with a variable stiffness device or a variable damping device interposed in a beam-column structure of a structure, and uses the variable-rigidity device to install the column-beam frame. There are various vibration control methods that evaluate the damping properties of structures by changing the stiffness or the damping coefficient of the variable damping device, and that use the damping force generated by the variable damping device as a control force. (See, for example, Japanese Patent Publication No. 7-42811 and Japanese Patent Publication No. 7-45781).

[0005]

A dynamic vibration absorber has been put into practical use relatively early as a vibration damping device because it has a simple principle and structure and does not require control.

However, the problems with the conventional dynamic vibration absorber including the spring and the damper as components are that it is difficult to actually tune the natural period of the weight to the natural period of the structure, and the stroke of the weight is reduced. The damper provided for the restriction hinders the swing of the weight in the initial state of the vibration, and the sufficient damping effect is not exhibited.

The present invention solves the above-mentioned problems by using a variable damper for a damper constituting a dynamic vibration absorber and performing a simple control to improve the initial rise of the vibration and improve the vibration damping effect. The purpose of the present invention is to simplify the control by introducing the concept of history control and history control, and to facilitate tuning of the natural period in implementation.

[0008]

According to the present invention, a variable damping device having a variable damping coefficient is conventionally used as a passive vibration damping device as a damper for a dynamic vibration absorber installed on the top or inside of a structure. Simple control is performed by control means such as a computer or a control circuit, and vibration control is performed by so-called semi-active control.

As a basic idea in the present invention,
Uses, as a dynamic vibration absorber incorporating the above-described variable damping device, a structure in which a structure and a weight movable in a horizontal direction with respect to the structure are connected by a spring and a variable damping device is interposed. The spring is basically used to synchronize the vibration of the weight with the vibration of the structure as in the case of the conventional dynamic vibration absorber. However, since the stiffness of the variable damping unit changes between 0 and k _d depending on the control state of the variable damping unit, which affects the period as the nonlinear dynamic vibration absorber, a combined analysis of the spring and the variable damping unit is performed. Setting is required.

By using such a non-linear dynamic vibration absorber, the amount of attenuation by the variable damper is controlled to be low in the initial stage of the response of the structure due to disturbance, and subsequently, the attenuation by the variable damper is increased as the response of the structure increases. Control the volume to a larger state. As a result, the rise at the beginning of the vibration is improved, and the response of the structure can be reduced at an early stage. That is,
In the early stage of the response of the structure due to the disturbance, the variable damping device
Control the amount of attenuation to a preset low state
As a result, the attenuation by the variable attenuator has been increased.
So that the weight starts to vibrate earlier,
Attenuation by variable damping device as the response of the structure increases
Control the weight to a larger state to reduce the vibration of the weight.
The response of the structure is reduced in synchronization with the vibration of the object.
is there.

According to a first aspect of the present invention, there is provided a vibration control method for a structure based on the above concept, further focusing on the restoring force characteristics of a dynamic vibration absorber incorporating a variable damping device, and controlling the vibration in a form of hysteresis control. Is what you do.

[0012] More specifically, or not a considered a restoring force characteristics with respect to vibration of the weight in the dynamic vibration reducer portion. The restoring force characteristic and resiliency given as the sum of the generated damping force F of the restoring force Q _s and a variable attenuator of a spring only _{Q (= Q s + F)} , can be considered as a relation of the amplitude of the weight.

Further, as a restoring force characteristic which gives a relationship between the amplitude D of the weight and the restoring force Q in a vibration state which changes every moment, a plurality of arbitrarily selected values can be set within a range controllable by the variable damping device (see FIG. 2). consider the restoring force characteristics for restoring force Q ₀ energy absorption characteristics is maximum (see FIG. 3), load the restoring force characteristics - shape parameters gives a shape on the coordinate plane representing the deformation relationships alpha = Q ₀ / (K・
Consider D).

That is, the amplitude D of the weight changes every moment in the process of damping due to the disturbance of the structure such as an earthquake or a wind, but by fixing the value of the shape parameter α, the restoring force on the coordinate plane is fixed. The characteristics (history shape) are kept similar.

Here, in the present invention, the value α that gives a low attenuation state in the early stage of the response of the structure due to the disturbance.
₁ (for example, α ₁ = 0) is controlled so as to give a restoring force characteristic, and subsequently, a value α ₂ (for example, α ₂ = 1) that gives a large attenuation state as the response of the structure increases. Control to give force characteristics.

[0016] By controlling in this manner, as well as improving the rise of the dynamic vibration reducer in the vibration initial, thereby maximizing the system capacity of the variable damping device regarding attenuation while simplifying the control law by the history control Can be.

According to a second aspect of the present invention, there is provided a method of damping a structure according to the first aspect of the present invention, wherein the rigidity K of the spring is determined in advance.
Small oscillation period than tunes the stiffness K ₀ to the vibration of the vibration structure of the weight in the absence of variable damping device may be set to longer than that the natural period of the structure, low shape parameters α of attenuation state the value gives the alpha ₁ (stiffness K ₁ of the combined spring portion and a variable attenuator portion of the variable damping device at this time, K <has the relation K ₁ <K ₀₎ values to provide a greater state of attenuation from alpha ₂ (At this time, the rigidity K ₂ of the spring portion and the variable damper portion of the variable damper is
K <K ₂ ≒ K ₀ ) so that the vibration period of the weight determined by the spring stiffness K and the parameter α approaches the natural period T ₀ of the structure. It is.

Table 1 summarizes the stiffness, period, and attenuation when the shape parameter α = 0 selected at the beginning of vibration and the shape parameter α = 1 selected at the time of continuous vibration control.

[0019]

[Table 1]

As described above, by selecting the shape parameter α, the cycle of the dynamic vibration absorber can be extended, and the cycle in mounting can be adjusted.

As the dynamic vibration absorber in the vibration damping methods of the first and second aspects, for example, a conventional dynamic vibration absorber using a variable damper as a damper can be used.

That is, a weight movable in the horizontal direction with respect to the structure, a spring for connecting the structure and the weight and tuning the vibration of the weight to the natural period of the structure, In a dynamic vibration absorber for a structure including a damper interposed therebetween, a variable damping device is used as the damper, and control means for changing a generated damping force of the variable damping device according to a response of the structure is provided. It is provided.
The response of the structure can be detected by a sensor such as a speed sensor or an acceleration sensor.

[0023]

FIG. 1 conceptually shows one embodiment of the present invention. As shown in FIG.
A non-linear dynamic vibration absorber 1 is installed at the top of the computer, and is controlled by a computer 5 based on information from a sensor 6 that detects the response of the building 10.

FIG. 1 (b) shows the structure of the nonlinear dynamic vibration absorber 1 as a dynamic model. The weight 2 is placed horizontally with respect to the building 10 via the tuning spring 3 and the variable damping device 4 arranged in parallel. Movably in the direction. In FIG. 1B, m is the mass of the weight 2, K is the spring rigidity of the spring 3, k _d
Is the device rigidity of the variable damping device 4 portion, and c is the variable damping device 4
(Variable).

When the building 10 vibrates due to a disturbance such as an earthquake or wind, the response of the building 10 is reduced by adjusting the weight 2 to the natural period of the building 10, which is the case with the conventional passive dynamic vibration absorber. However, by controlling the variable damping device 4 so that the amount of attenuation is low in the early stage of the response of the building 10 detected by the sensor 6, the rigidity K of the spring 3 mainly works, and the amount of attenuation of the variable damping device 4 As a result, the rise as a dynamic vibration absorber is improved. That is, the weight 2 starts to vibrate early.

Subsequently, with the weight 2 starting to vibrate,
By shifting the damping amount of the variable damping device 4 to a large state, the rigidity of the variable damping device 4 portion also starts to take effect. By setting the rigidity and damping properties of the spring 3 and the variable damping device 4 portion in advance, the weight is reduced. 2 can be tuned to the natural period of the building 10, and the response of the building 10 can be reduced early and efficiently.

[0027] Figure 2 is a variable restoring force characteristic in the attenuation nonlinear dynamic vibration absorber incorporating the device, i.e. generated damping force of the restoring force Q _s and a variable damping device 4 of the spring 3 in the configuration of FIG. 1 F
Relationship of the sum Q (= Q _s + F) and the displacement x of the weight 2, and shows the relationship between these and the structural constraints.

The restoring force characteristic of the non-linear dynamic vibration absorber when the weight is oscillating in a steady state with the amplitude D is within the range of the parallelogram shown by hatching in FIG. 2 due to the structural restriction of the variable damper (variable dashpot). Can only take.

In FIG. 2, β is a rigidity ratio [= (K + k _d ) /K≧1.0] between the rigidity K of the spring alone and the overall rigidity including the rigidity k _d of the variable damping device, and βK Gives the inclination of the upper and lower sides of the parallelogram.

[0030] In the present gun onset bright performs control so that a shape restoring force characteristics are set in this structural constraints.

Here, for example, as shown in FIG. 3, the shape of the restoring force characteristic represented on the coordinate plane is represented by a shape parameter α.
[= Q ₀ / (K · D)] (0 ≦ α ≦ 2β−
1, Q ₀ is the maximum value set for the restoring force (acceleration) for the control of the variable damping device under specific conditions where D is fixed).

FIG. 3 shows that β = 1.5, ie, k _d / K =
0.5, the shape parameter α = 0, 0.5, 1..
Restoring force Q on the left for five types of 0, 1.5, and 2.0
And a graph showing the relationship between the displacement x of the weight (restoring force characteristic) and the graph showing the relationship between the generated damping force F of the variable damping device and the displacement x of the weight on the right side.

Here, in the early stage of the response of the building, the weight starts to vibrate early by controlling the amount of attenuation to be low, for example, α = 0.

Subsequently, when the weight starts to oscillate, for example, by selecting α = 1 to shift the attenuation of the variable damping device to a large state, the response can be reduced at an early stage.

The basic concept of the continuation of the vibration control after the vibration control is started is that a certain amplitude D at a certain time is used.
Hereinafter, the restoring force characteristics are set so that the absorbed energy is maximized at a fixed restoring force (acceleration) Q ₀ or less, and the restoring force characteristics are controlled with respect to the amplitude D (t) that changes every moment.

FIG. 4 is a flow chart showing an example of the control procedure.

First, the response amount of a structure (building) when a disturbance such as an earthquake or wind acts is measured by a sensor attached to the building.

Next, regarding the setting of the shape parameter α,
In the initial vibration or in the small vibration state, for example, α = 0 (not limited to 0) with a small attenuation is set.

When the vibration becomes large, a large amount of attenuation, for example, α = 1 (not limited to 1) is set.

The shape (history shape) of the restoring force characteristic of the dynamic vibration absorber represented on the coordinate plane by the variable damping device is simplified by controlling the shape parameter α selected as described above. In this case, the efficiency of the dynamic vibration absorber can be improved. This also effectively reduces the response of the structure.

On the other hand, the period (tuning period) and the damping constant of the dynamic vibration absorber can be adjusted by controlling (changing) the hysteresis of such a nonlinear dynamic vibration absorber. FIG. 5 shows the shape parameter α under specific conditions.
Is a graph showing changes in the period T (equivalent period) and the damping constant h (equivalent damping constant) of the dynamic vibration absorber when the value of is changed.

As shown in FIG. 5, the shape parameter α uniquely corresponds to the period of the dynamic vibration absorber. Accordingly, the rigidity K of the spring is set small in advance, and after the dynamic vibration absorber starts up in a state where the shape parameter α is small, the state shifts to a state where the shape parameter α for giving the original response reduction effect is large. By setting the shape parameter α to a value that gives the tuning period to the weight of the dynamic vibration absorber, both the period of the dynamic vibration absorber and the damping constant are changed to perform very efficient vibration control be able to.

According to the vibration damping method of the present invention, the initial rise of structural vibration in the dynamic vibration absorber as the vibration damping device is improved, the vibration damping effect is exhibited early, the increase in response is suppressed, and the response is reduced early. The effect is obtained.

[0044] In addition, a simplified control by introducing the concept of history control using shape parameters alpha, and enables efficient control.

According to the vibration control method of claim 2 of the present application,
Since the period of the dynamic vibration absorber can be adjusted by setting the shape parameter α, the natural period can be easily tuned in mounting.

[Brief description of the drawings]

FIGS. 1A and 1B conceptually show an embodiment of the present invention. FIG. 1A is a conceptual diagram of the entire system, and FIG. 1B is a diagram showing the configuration of a nonlinear dynamic vibration absorber as a dynamic model.

FIG. 2 is a diagram illustrating a relationship between a restoring force characteristic and a structural constraint in the nonlinear dynamic vibration absorber.

FIG. 3 is a graph showing the relationship between the restoring force Q and the displacement x of the weight (restoring force characteristic) for five types of shape parameters α = 0 to 2.0, and the right side shows the generated damping force F of the variable damping device. And a graph showing the relationship between the weight and the displacement x of the weight.

FIG. 4 is a flowchart illustrating an example of a control procedure.

FIG. 5 is a graph showing a relationship between a shape parameter α and changes in a natural period T and a damping constant h of the dynamic vibration absorber.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Nonlinear dynamic vibration absorber, 2 ... Weight, 3 ... Spring, 4 ... Variable damping device, 5 ... Computer, 6 ... Sensor, 10 ... Building

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E04H 9/02 F16F 15/02

Claims (2)

(57) [Claims] 1. A structure and a weight movable in a horizontal direction with respect to the structure are connected by a spring having a rigidity K for synchronizing the vibration of the weight with the vibration of the structure, and are variable in parallel with the spring. a vibration control method of a structure that uses nonlinear dynamic vibration absorber formed by providing a damping device, the generated damping of the variable damping device for varying the restoring force Q _s and stiffness of the spring only between 0 to k _d Restoring force Q (= Qs + F) given as the sum of force F and amplitude D of the weight
Loading the restoring force characteristic is a relationship, in a controllable range by the variable damping device, the restoring force characteristic energy absorption characteristics is maximized with respect to a plurality of arbitrary restoring force Q ₀ and - coordinates representing the deformation relationships A shape parameter α = Q ₀ / (K · D) to be given as a shape on a plane is obtained in advance, and a restoring force characteristic corresponding to a value α ₁ giving a low attenuation state in the initial stage of the response of the structure due to a disturbance is obtained. By controlling to give, the weight starts to vibrate earlier as compared with the state where the attenuation by the variable damping device is increased, and then the state where the attenuation is large with the increase of the response of the structure. by controlling so as to provide a restoring force characteristics for the value alpha ₂ to give, seismic response control method of the structure, characterized in that to reduce the response of the tuned in structure to the vibration of the vibrating structure of the weight. 2. A method in which the rigidity K of the spring is set in advance in a state where the vibration of the weight is smaller than the rigidity K _{0 in} which the vibration of the weight is synchronized with the vibration of the structure without the variable damping device, and the vibration period is longer than the natural period of the structure. It may be set to, the by the shape parameter alpha from the values alpha ₁ to give a low state of said attenuation be transferred to the value alpha ₂ which gives a large state of the attenuation of the weight determined with the spring by the parameter alpha Damping method according to claim 1 structure according vibration period and sets to approach the natural period of the structure.