JPH08151820A - Damping coefficient adjustment type vibration control device - Google Patents

Abstract

(57) [Abstract] [Purpose] The simple control mechanism keeps the damping added by the device high even when the vibration cycle of the building fluctuates or in the situation where high-order vibration is dominant, and (EN) Provided is a damping coefficient adjusting type vibration damping device capable of enhancing comfort. [Structure] The variable damping device 1 is installed between a beam 32 and a brace 33 of a column / beam frame. The displacement x of the column / beam frame when an external vibration force such as an earthquake is applied is measured by the displacement meter 34 and input to the control circuit 40. The displacement x is differentiated by the differentiating circuit 41 to obtain the response acceleration a. From the displacement x and the acceleration a, the vibration frequency ω _t of the column / beam frame is obtained by the frequency identification circuit 42. To the extent the displacement x and the acceleration a is small, in consideration of an error provided upper and lower limits of the omega _t, replacing omega _t in omega _t 'by omega _t limiting circuit 43. By inputting ω _t ′, in the damping coefficient calculation circuit 44, _ct = K _b / [ω _t '
(1 + N) performs an operation ^1/2], with respect to the variable damping device 1 outputs a command of the damping coefficient c _t.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping coefficient adjusting type damping device for imparting a high damping property to the response of a structure to an external vibration force such as an earthquake or wind and reducing the vibration.

[0002]

2. Description of the Related Art A variable damping device for a seismic control structure is installed in a frame of a structure, and the damping coefficient of the device is actively changed according to the characteristics such as individual earthquakes and external wind forces. The damping resistance reduces the sway of the structure, and the control means using a computer or the like can perform the control in which the damping property of the structure is evaluated.

As such a variable damping device for a vibration control structure, there is, for example, the one described in JP-A-2-289769.

FIG. 4 shows an example of such a variable damping device as a hydraulic circuit diagram, in which hydraulic chambers 6 are provided on the left and right of a double rod type piston 3 which reciprocates in a cylinder 2.
By closing or flowing the pressure oil in the left and right hydraulic chambers 6 with a valve, the piston 3 is fixed or movable left and right.

Then, the cylinder 2 and the rod 4 are respectively connected to the main body of the column / beam frame of the structure or seismic resistant elements such as braces and seismic walls to provide damping resistance against deformation of the column / beam frame.

The left and right hydraulic chambers 6 respectively include an outflow prevention check valve 8 for preventing the pressure oil from flowing out of the hydraulic chamber 6 and an inflow prevention check valve 9 for preventing the pressure oil from flowing into the hydraulic chamber 6.
Is provided, and an inflow passage 10 that connects the left and right outflow prevention check valves 8 and an outflow passage 11 that connects the left and right inflow prevention check valves 9 are provided.

These inflow channel 10 and outflow channel 11
A flow rate control valve 12 is provided at the connecting position of, and the damping coefficient c of the variable damping device 1 can be adjusted by changing the opening degree of the flow rate control valve 12.

Further, in this example, the flow rate control valve 12 has a large flow rate switching valve 12a having an inlet port 15 and an outlet port 16 on one end side of the valve body and a back pressure port 17 on the other end side.
A shut-off valve 12b capable of controlling the outflow of pressure oil to the back pressure port 17, and in response to a command from the computer 14, the shut-off valve 12b opens and closes, and the large flow rate switching valve 12a operates accordingly. Then, the opening degree of the large flow rate switching valve 12a and the damping coefficient c of the device according to the opening degree are adjusted and controlled.

That is, by adjusting the opening degree of the flow control valve 12 and finely adjusting the connection state between the completely locked state and the completely free state, various damping coefficients c are given, and the damping coefficients c and According to the vibration state of the frame body, the natural period of the frame body and the damping constant h of the frame body at that time are given.

Further, the inflow passage 10 or the outflow passage 1
1 is provided with an accumulator 19 and the like for the purpose of compensating for volume change due to compression of hydraulic oil and temperature change.

[0011]

When the damping coefficient c of the variable damping device is changed to reduce the response of the building frame, various control laws using various parameters can be considered. With such changes, the natural frequency of each order of the column / beam structure and the entire building changes, the damping constant h also changes accordingly, and when the natural frequency of higher than 2nd order is predominant. There are various factors that complicate the rule.

On the other hand, it is possible to perform a complicated analysis by a computer based on a signal from a sensor or the like installed inside or outside the building or in a device section, but it is costly and the device is not required. Stability related to the operation and control of is likely to cause problems.

According to the present invention, the relatively simple control mechanism keeps the damping addition by the device high even when the vibration period of the building fluctuates or in the situation where the higher order vibration is predominant. It is an object of the present invention to provide a damping coefficient adjusting type vibration control device capable of enhancing comfort.

[0014]

The damping coefficient adjusting type vibration damping device of the present invention is provided between a column / beam frame of a structure and a seismic resistant element such as a brace or an earthquake resistant wall provided in the column / beam frame. The installed variable damping device, response detecting means such as a sensor for detecting the response of the pillar / beam frame, and control means for adjusting the damping coefficient of the variable damping device according to the response value obtained by the response detecting means. In the seismic control device, the control means identifies the vibration frequency ω _t of the column / beam frame at every moment based on the response value obtained by the response detection means, and the identified vibration frequency ω _{t. At t} , the optimum damping coefficient c _opt that maximizes the damping coefficient h of the column / beam frame is calculated based on the following equation (1), and variable damping is performed by the output of the optimum damping coefficient calculating means. The damping factor of the device The damping coefficient control means controls the optimum damping coefficient c _opt .

[0015]

(Equation 3)

(Where N = K _b / K _f ) where K _b is the rigidity of only the seismic resistant element, K _f is the rigidity of only the column / beam structure, and ω _t is the column / beam including the seismic resistant element at a certain time. The vibration frequency of the entire frame.

The pillar / beam frame of a layer of a high-rise building, the brace as a seismic element, and the variable damping device can be modeled as shown in FIGS. 2 and 3. The complex stiffness K _C of the layer when this layer is subjected to sine wave excitation with a frequency f (Hz) is expressed by the following equation.

[0018]

[Equation 4]

(Where ω = 2πf) Here, the damping constant h of the layer can be expressed by the following equation.

[0020]

(Equation 5)

(However, K _R = K _C real part, K _I = K
(Imaginary part of _C ) To find c that maximizes h, set dh / dc = 0

[0022]

(Equation 6)

It becomes

If the ratio of the frame rigidity K _f to the brace rigidity K _b is set as K _b / K _f = N, then equation (4) is

[0025]

(Equation 7)

It can be expressed as

Therefore, c which maximizes the damping constant h of the layer
_It can be seen that _opt is determined by the values of K _f , K _b , and ω. Of these, K _f and K _b are determined by the specifications at the time of design, so it is sufficient if the vibration frequency ω (= 2πf) can be identified.

There are various possible means for identifying ω, but here, for example, the following simple method (corresponding to the inventions of claims 2 and 3 of the present application) is proposed.

Now, assuming that the amplitude of the device section is x = D sinωt, the velocity v and the acceleration a are v = ωD cosω
Since t and a = −ω ² D sin ωt, ω can be identified by the following equation. If the identified ω is ω _t ,

[0030]

(Equation 8)

## EQU1 ##

However, when x and a are very small, the error of ω _t may be large. Therefore, the following limit is set and ω _t ′ is set.

Ω _L ≦ ω _t '≦ ω _U (7) Here, ω _L is a lower limit value, for example, about ½ of the primary frequency of the building, and ω _U is an upper limit value, for example, It can be about the third frequency of the building. Of course, appropriate lower limit value ω _L and upper limit value ω _U may be set according to the condition of the building.

By substituting this into the equation (5), the damping coefficient c _t that the device should take at a certain time is

[0035]

[Equation 9]

It becomes

As a result, it is possible to realize a seismic control structure that exerts great effects with a very simple system.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention.
As shown in FIG. 1 (a), the variable damping device 1 is installed between the upper beam 32 and the inverted V-shaped brace 33.

In the figure, reference numeral 34 is a displacement gauge, which measures the horizontal displacement x between the beam 32 constituting the column / beam frame and the brace 33 as a seismic resistant element.

Displacement x when an external vibration force such as an earthquake or wind acts is input to the control circuit 40 every moment, and in this control circuit 40, the vibration frequencies ω _t and ω of the column / beam frame.
calculation for obtaining the pillars, Harika構the damping constant h a momentary maximizing optimum damping coefficient c _opt (c _t) is performed at _t, the optimum damping coefficient c which is output to the attenuation coefficient of the variable damping device 1 _By controlling to give _opt ( _ct ),
It is possible to add a high damping property to the pillar / beam structure.

The block diagram of FIG. 1 (b) shows a specific configuration of the control circuit 40, which comprises a differentiation circuit 41, a frequency identification circuit 42, a ω _t limiting circuit 43, and a damping coefficient calculation circuit 44.

The differential acceleration 41 is obtained by differentiating the displacement x input from the displacement meter 34 by the differentiating circuit 41.

The frequency identification circuit 42 is a circuit for calculating the above-mentioned equation (6), and the vibration frequency ω _t in the response of the column / beam frame is calculated from the displacement x and the acceleration a given by the differentiating circuit 41. I want it.

The ω _t limiting circuit 43 is a circuit which applies the limiting condition of the above-mentioned equation (7) and replaces ω _t with ω _t '.

The damping coefficient calculation circuit 44 is a circuit for calculating the above-mentioned equation (8), and by inputting ω _t 'or ω _t , the optimum damping coefficient c of the variable damping device 1 to be controlled.
Output _opt ( _ct ).

[0046]

The vibration frequency ω _t in the column / beam frame is calculated every moment by using the sensor provided in the device section, and the damping constant h is obtained by the simple control mechanism based on the identified vibration frequency ω _t. Since the optimum damping coefficient c _opt that maximizes the value is given to the device, the damping addition by the device is kept high even when the vibration period of the building fluctuates or in the situation where high-order vibration is dominant. Safety and comfort can be improved.

[Brief description of drawings]

1A and 1B show an embodiment of the present invention, in which FIG. 1A is a schematic view of an apparatus installed on a pillar / beam frame, and FIG. 1B is a block diagram of a control circuit in FIG. 1A.

FIG. 2 is a schematic diagram showing a positional relationship between a pillar / beam structure and a variable damping device of a high-rise building when the present invention is applied.

FIG. 3 is a diagram showing a model of one layer.

FIG. 4 is a hydraulic circuit diagram of a conventional variable damping device.

[Explanation of symbols]

1 ... Variable damping device, 2 ... Cylinder, 3 ... Piston, 4 ...
Piston rod, 6 ... Hydraulic chamber, 8 ... Outflow prevention check valve, 9 ... Inflow prevention check valve, 10 ... Inflow passage, 1
DESCRIPTION OF SYMBOLS 1 ... Outflow passage, 12 ... Flow control valve, 13 ... Valve opening controller, 14 ... Computer, 15 ... Inlet port, 1
6 ... Exit port, 17 ... Back pressure port, 18 ... Displacement meter, 1
9 ... Accumulator, 31 ... Pillar, 32 ... Beam, 33 ... Brace, 34 ... Displacement meter, 40 ... Control circuit, 41 ... Differentiation circuit, 42 ... Frequency identification circuit, 43 ... ω _t limiting circuit, 44
... Attenuation coefficient calculation circuit

Claims (3)

[Claims] 1. A variable damping device installed between a pillar / beam frame of a structure and a seismic element provided in the pillar / beam frame,
In a vibration control device comprising a response detection means for detecting the response of the pillar / beam frame, and a control means for adjusting the damping coefficient of the variable damping device according to the response value obtained by the response detection means, The control means identifies the vibration frequency ω _t of the pillar / beam frame based on the response value, and the identified vibration frequency ω _{t.
At t} , the optimum damping coefficient c _opt for maximizing the damping coefficient h of the column / beam frame is calculated based on the following equation (1), and the optimum damping coefficient calculating means outputs the optimum damping coefficient c _opt. A damping coefficient adjusting type damping device, comprising: damping coefficient control means for controlling the damping coefficient of the variable damping device to an optimum damping coefficient c _opt . [Equation 1] (However, N = K _b / K _f ) 2. The damping coefficient adjusting type damping device according to claim 1, wherein the response detecting means is a displacement gauge for measuring a displacement x between the column / beam frame and the seismic resistant element at the variable damping device installation position, The vibration frequency identifying means identifies a momentary vibration frequency ω _t from the displacement x and the acceleration a based on the following equation (6), and a differentiation circuit for obtaining the acceleration a from the displacement x continuously measured by the displacement meter. A damping coefficient adjusting type damping device, which is characterized by comprising a frequency identification circuit that operates. [Equation 2] 3. The damping coefficient adjusting type damping device according to claim 2, wherein a predetermined lower limit value ω _L and an upper limit value ω _U are set for a range in which the displacement x and the acceleration a are smaller than a predetermined value, and to the vibration frequency omega _t, provided the vibration frequency limiting circuit providing a omega _t 'due to a limitation in the following equation (7), wherein
(1) attenuation coefficient adjusting type vibration control device, which comprises using the omega _t 'instead of omega _t for expression. ω _L ≤ ω _t '≤ ω _U …… (7)