JPH0522028B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a variable rigidity brace used in seismic damping structures.
The rigidity of the frame changes according to external forces such as wind to cope with earthquakes, etc.

[Conventional technology]

Conventionally, in the seismic design of high-rise buildings and important structures, dynamic design has been performed to check safety by calculating the ground movement and building response during an earthquake.

Earthquake resistance methods include seismic isolation or attenuation construction methods in which laminated rubber bearings or dampers are interposed between the building and the foundation, methods that consume earthquake energy by destroying non-main building components, walls or columns. There is a method to adjust the rigidity of the building to the optimum level by creating slits in the building.

By the way, confirmation of the safety of buildings designed using current seismic design methods in the event of an earthquake is based on the basic idea that the energy absorbed by the hysteresis characteristics associated with plasticization of the structure exceeds the seismic energy acting on the structure. However, this has the problem of reliability regarding the history loop characteristics.

In addition, all conventional methods provide a passive earthquake-resistant structure against natural external forces such as earthquakes and wind, and because buildings have a specific natural frequency, they cannot resist resonance phenomena in response to uncertain inputs such as earthquakes. You cannot avoid it.

In contrast, in Japanese Patent Application Laid-Open No. 62-268479, the applicant proposed an active method to improve the stiffness of a building based on the judgment of a response prediction system based on the detected seismic motion, rather than using the passive seismic resistance method described above. We are proposing a vibration damping method that aims at the safety of buildings, equipment inside buildings, occupants, etc. by changing the vibration to a state where resonance is outside the resonance region or with little resonance.

In the above seismic control method, a control device is installed in all or part of columns, beams, braces, walls, and their joints, or between a building and the foundation or an adjacent building, so that the connection state can be changed according to computer commands. , Damping the building is done as follows.

The occurrence of an earthquake is detected by earthquake sensing devices placed in both narrow and wide areas around buildings, and the observation data is transmitted to a computer via wired and wireless communication networks. A wide-area earthquake detection method connects seismometers at existing earthquake observation points or specially installed ones using microcircuits or telephone lines. In addition, narrow-area earthquake sensing devices consist of seismometers installed around buildings or in the surrounding ground, and vibration sensors installed at the base of buildings or inside buildings, and the effects of wind force etc. are detected by vibration sensors inside buildings.

For detected earthquakes, a computer determines the scale of the earthquake, analyzes frequency characteristics, predicts the amount of response, etc., and determines whether or not to control the vibration of the building, and if so, the amount of control to avoid resonance. The judgment is made based on the one that provides the optimum stiffness (natural frequency) with a small amount of seismic response.

The computer's commands are transmitted to the control devices in each part of the building, and the control devices operate so that the building's stiffness reaches the optimal stiffness based on the computer's predictions. The connection state can be adjusted by turning the fixed state and uncoupled state on and off using hydraulic mechanisms, electromagnets, etc., or by applying tension or fixing at any position between the fixed state and uncoupled state using a hydraulic mechanism. Alternatively, it may be adjusted using a special alloy or the like.

In addition, vibration sensors placed inside the building will
The amount of response in each part of the building as well as the actual vibration when the control is performed can be sensed, and this can be fed back to correct the amount of control.

In addition, conventional ways of thinking about variable-rigidity buildings include, for example, expanding and contracting the braces within the structural surface surrounded by columns and beams, varying the rigidity of the braces themselves, or changing the connection state between columns or beams and braces. Control is performed by changing the rigidity of the frame by switching on and off (JP-A-63-70734, JP-A-63-114770, JP-A-1-127741).
No., JP-A No. 1-127742, JP-A No. 1-131741, etc.).

[Problem to be solved by the invention]

By the way, in order to fully demonstrate the effect of the above-mentioned variable stiffness building, it is necessary to be able to change the stiffness instantaneously and to minimize mechanical delays.

The object of the present invention is to provide a variable rigidity brace that has a simple structure, operates quickly, and reliably, as a variable rigidity device used in a variable rigidity building.

[Means to solve the problem]

Hereinafter, an overview of the present invention will be explained using reference numerals in the drawings corresponding to the embodiments.

The variable rigidity brace for vibration damping structures of this invention is
A restraint device that connects the braces 3 and 4 with a hinge 5 in the center and pin-joins both ends to the column-beam frame, and the hinge 5 and the column 1 or beam 2, and can control the restraint state of the hinge 5 position. 6, and a control device that controls the restraint state of the restraint device 6 in response to earthquake motion.

As the restraint device 6, it is possible to use a hydraulic, pneumatic, or electromagnetic brake mechanism, a hydraulic cylinder that can release the restraint state by releasing the hydraulic pressure, or a damper that can release the restraint state. By controlling the restraining device 6 to restrain or free the position of the hinge 5, and by making the braces 3 and 4 incorporating the hinge 5 effective or ineffective, the rigidity of the entire building can be varied. I can do that.

〔Example〕

Next, the illustrated embodiment will be described.

FIG. 1 shows an embodiment of this invention.
Within the structure surrounded by the pillars 1 and beams 2, hinges 5 are provided at the center of each of the two braces 3 and 4 installed in a V-shape, and the hinges 5 and the pillars 1,
A hydraulic cylinder-type restraint device 6 is connected to the intersection of the beams 2.
is tied.

Both ends of each of the braces 3 and 4 and both ends of the restraint device 6 are each pin-jointed and can rotate freely.

This figure 1 shows the initial state of the frame.
A predetermined rise (indicated by H in the figure) is provided in advance at the hinge 5 position of the braces 3 and 4. That is, with respect to the straight line connecting both ends of each brace 3, 4,
The position of the hinge 5 is shifted by H, so that when the column-beam frame is deformed, the hinge 5 can rotate smoothly, and when the frame is deformed, the braces 3 and 4 are
The brace 3,
4 becomes ineffective. This rise H makes it possible to prevent the braces 3 and 4 from fully extending even during maximum deformation of the building.

Figures 2 and 3 show the variable stiffness brace in operation.

When the frame deforms, the hinge 5 at the center of the braces 3, 4 tries to move, but if this is restrained by the restraining device 6, the braces 3, 4 can bear tensile force as well as compressive force. FIG. 2 shows this brace tensioned state.

Moreover, if the restraint state of the restraint device 6 is released and loosened, the hinge 5 at the center of the braces 3, 4 can move freely, and the braces 3, 4 do not bear any force. FIG. 3 shows this brace in a relaxed state.

The concept of variable stiffness control can be carried out in the same way as that described in the conventional technology section, and whether the restraint device 6 is in a restrained state or in a relaxed state is determined separately from the dominant periodic component of the earthquake motion, etc. In this regard, control is performed using a control device using a computer or the like to achieve the selected appropriate building rigidity.

4 to 6 show various modifications of the variable rigidity brace for vibration damping structures of the present invention.

In the embodiment shown in Fig. 1, the braces 3 and 4 are installed in a V-shape, whereas in Figs. 4 and 5, the braces 3' and 4' are installed in an X-shape, For example, the center part of braces 3' and 4', column 1, and beam 2
In the embodiment shown in FIG. 5, the center portions of the braces 3', 4' and the lower beam 2 are connected by the restraint device 6.

Further, in the embodiment shown in FIG. 6, a restraining device 6 is connected between the center portions of the braces 3 and 4 installed in a V-shape and the center portion of the lower beam 2.

[Effect of the invention] By adjusting the restraining state of the restraint device that connects the hinge provided at the center of the brace and the column-beam frame, the brace incorporated in the column-beam frame can be made to work or not. is possible,
The rigidity of the building can be made variable.

Since the hinge position is controlled by restraining and releasing the restraint, no unreasonable force is applied to the brace.
Since the frictional force is small, there is little mechanical delay,
Can be activated immediately. In particular, by providing a predetermined rise as an initial deflection at the hinge position, the hinge can be rotated smoothly when the frame is deformed.

The brace itself only requires a hinge in the center and does not require any particularly complicated cross-sectional changes, so it is easy to design, simple in structure, and highly reliable in operation.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of the present invention, FIGS. 2 and 3 are schematic diagrams showing the operating state of the device, and FIGS. 4 to 6 are schematic diagrams showing various modifications. . 1... Column, 2... Beam, 3, 4... Brace, 5
... Hinge, 6 ... Restraint device, 7 ... Pin joint.

Claims (1)

[Scope of Claims] 1. A brace having a hinge in the center and pin-joined at both ends to the column-beam frame, and a restraint that connects the hinge to a column or a beam and can control the restraint state of the hinge position. 1. A variable rigidity brace for a seismic damping structure, comprising: a device; and a control device that controls a restraint state by the restraint device according to seismic motion. 2. The variable rigidity brace for a seismic damping structure according to claim 1, wherein the restraint device connects the intersection between the column and the beam and the hinge.