JPH0370072B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a material with variable stiffness against axial tensile force used in a building frame with a damping structure.
The rigidity of the members is changed in response to external forces such as earthquakes and wind that enter the building to cope with earthquakes and the like.

[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 seismic structure against natural external forces such as earthquakes and wind, and because buildings have a specific natural frequency, they do not allow resonance phenomena to occur against uncertain inputs such as earthquakes. You can't avoid it.

In contrast, in Japanese Patent Application No. 61-112026 (Japanese Unexamined Patent Publication No. 62-268479), the applicant proposed a method based on the judgment of a response prediction system based on the detected seismic motion, rather than the passive seismic method described above. We are proposing a vibration damping method that changes the rigidity of the building itself to bring it out of the resonance region or into a state with less resonance, thereby ensuring the safety of the building, its equipment, residents, etc.

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. Wide-area earthquake sensing equipment connects seismometers at existing earthquake observation points or specially installed equipment using micro-wires 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 commands from the computer are transmitted to the control devices in each part of the building, and the control devices are operated so that the stiffness of the building 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., and in addition to the fixed state and disconnected state,
It is conceivable to use a hydraulic mechanism or a special alloy to adjust the introduction of tension force and fixation at an arbitrary position.

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 controlled can be detected, and this can be fed back to correct the amount of control.

[Purpose of the invention]

The variable rigidity material of the building frame of the present invention is used for braces, columns, etc. in the above-mentioned vibration damping method to change the tensile rigidity in the axial direction so as to be able to cope with earthquakes and the like. Note that this invention is not limited to use in the above-mentioned vibration control method, but can also be used in an improvement method of the above-mentioned method,
Alternatively, it can also be used simply to change stiffness.

[Structure of the invention]

The variable rigidity material of the present invention is used in a building frame to act as a resistance member or a non-resistance member against tensile force in the axial direction, and is made up of two or more pieces as shown in Fig. Consisting of 1a and 1b,
With their ends butted against each other, the pieces 1a and 1b can be restrained by the restraining material 3 to resist the tensile force, or the restraint of the pieces 1a and 1b can be released to make them non-resistant to the tensile force. .

The restraint member 3 is provided on one piece 1a and is operated by a drive device such as a servo motor or a pulse motor. As a restraint method, the restraint member 3 was moved parallel to the direction perpendicular to the axial direction of the piece 1a along the bolt 5 by a ball screw 6 provided on the restraint member 3, and was provided at the ends of the opposing pieces 1a and 1b. Possible methods include engaging or disengaging the locking protrusions 2a and 2b at the same time. Also,
It is desirable to connect the pieces 1a, 1b with a connecting material 4, such as a steel bar, whose tensile rigidity is sufficiently lower than that of the pieces 1a, 1b, so that the pieces 1a, 1b do not separate and their axes shift. In that case, the connecting member 4
are provided on two opposing sides of the variable rigidity member 1 so as not to be eccentric.

A drive device such as a servo motor can be operated by a computer control program. In other words, it is possible to control the rigidity using a computer in response to external vibrational forces such as earthquakes, and by changing the rigidity, connection state, etc. of members in each part of the building,
Resonance can be avoided by changing the natural period of the building as a whole.

〔Example〕

Next, the illustrated embodiment will be described.

FIGS. 2a to 2d show an embodiment of the present invention, in which one structural member is divided into pieces 1a and 1b, which are connected by a connecting member 4 having low tensile rigidity, such as a steel bar. In the figure, reference numerals 7a and 7b are mounting flanges for attaching the connecting member 4 to both sides of the pieces 1a and 1b.

Each of the pieces 1a and 1b has locking protrusions 2a and 2b protruding from two opposing surfaces, respectively, to which the resistance force of the cross section of the member can be transmitted. A restraining member 3 that can simultaneously engage with the locking protrusions 2a and 2b of these pieces 1a and 1b is provided on each surface, and is movable in a direction perpendicular to the material axis of the variable rigidity member 1. It comes into contact with and separates from the protrusions 2a and 2b. When they come into contact, the restraining material 3 is caught on each locking protrusion 2a, 2b and can resist the tensile force in the axial direction, and when they are separated, the restraining material 3 cannot resist the tensile force, and only the connecting material 4 It becomes resistance. The tensile rigidity of the connecting member 4 is sufficiently smaller than that of the pieces 1a and 1b of the main body of the variable rigidity member 1.

The restraining member 3 is moved by fixing the nut portion of the ball screw 6 to the restraining member 3 and rotating the bolt 5. In this embodiment, a bolt 5 is provided at the center of the cross section of one piece 1a, and gears 9a, 9 are driven by the rotation of a computer-controlled motor 8.
It is rotating through b. The bolt 5 is rotatably supported by a support base 10 and a support 11 fixed to the piece 1a, and each of the restraining members 3 provided on two sides of the piece 1a has opposite threads. As a result, the two restraining members 3 simultaneously move symmetrically with the rotation of one motor 8.
If the restraining member 3 has a symmetrical shape with respect to the bolt 5, stability is improved. In addition, in this embodiment, a slider 12 is provided on the piece 1a side of the restraining material 3, and the piece 1
The restraining member 3 is prevented from rotating by sliding along a rod-shaped guide member 13 that passes through a.

3 and 4 respectively show modified examples of the drive mechanism. In the example of FIG. The figure shows a case where the support 11' of the bolt 5 is directly attached to the piece 1a without providing a support stand. In the figure, reference numeral 14 denotes a stopper for restricting movement of the restraining member 3.

FIGS. 5a to 5d show another embodiment in which the drive mechanism is provided on the side of the piece 1a. That is, the bolt 5 and the nut of the ball screw 6 for moving the restraining member 3 in parallel are connected to the piece 1.
a and the restraining member 3, and on the opposite side, a guide member 13' and a slider 12' fixed to the restraining member 3 are provided, and the motor 8 is connected to the piece 1.
It is supported by a bracket 15 projecting to the side of a, and the bolt 5 is rotated via gears 9a and 9b. In FIGS. 5a to 5d, there is also a method in which a ball screw 6 and a motor 8 are provided on both sides of the piece 1a, and the motors 8 are synchronized to operate the restraining member 3.

Fig. 6 shows an example of the case where the brace is applied to a building frame. When the pieces 1a and 1b of the variable rigidity member 1 are restrained by the restraining member 3, the axial direction is It has a structure that can resist compressive force and tensile force, but when the restraining material 3 is released, it has a structure that cannot resist tensile force,
The rigidity of the entire building will also change.

Figures 7a and 7b are examples of the case where the variable rigidity material 1 of the present invention is used as earthquake columns on both sides of the axial force column 16 on the lowest floor of the building. As shown in Fig. 7b, by releasing one of the restraints or moving from the restraint release state to the restraint state,
Rigidity can be changed in response to earthquakes, etc.
In the figure, 17 is a brace or a seismic wall.

FIGS. 8 and 9 show an embodiment in which the rigidity is varied with respect to the axial tensile force, and the rigidity is also varied with respect to the axial compressive force, and is applied to a brace. That is, piece 1b' and piece 1c' (Fig. 8) or piece 1a' and piece 1b' (Fig. 9) of variable rigidity member 1' are connected by pin 21, and by restraint member 22 extending from one piece, The rotation of the other piece can be restrained or released to resist the compressive force (when restrained), or it can be made non-resistant to the compressive force (when the restraint is released). In the example shown in Fig. 8, the variable stiffness material 1' is made up of three pieces 1a', 1b',
1c', the restraining member 3 moves in parallel in the plane between piece 1a' and piece 1b' so as to have variable stiffness against the tensile force, and between piece 1b' and piece 1c' A pin 21 is provided that can rotate within a plane so as to have variable rigidity. On the other hand, in the example shown in FIG.
1b', the restraining member 3 related to tensile force is configured to move in an out-of-plane direction, and the pin 21 related to compressive force is configured to move in an out-of-plane direction.
Some parts are considered loose balls.

Figures 10a and 10b show the case where the variable rigidity member 1' is also used as an axial force column, and Figure 10a shows a state in which both of the variable rigidity members 1' are resisting both compressive force and tensile force.
Figure 10b shows a state in which the axial force column on the left side of the figure can resist tensile force but not compressive force.
The image on the right shows a state in which the building can resist compressive forces but not tensile forces, and the stiffness of each column and the building as a whole can be changed in response to individual earthquakes.

[Effects of the invention] Pieces constituting members can be connected together,
The connection can be released and the stiffness of the member can be varied in response to axial tensile forces. In addition, since connection and disconnection are performed by engaging and disengaging the locking protrusion provided at the connecting end of the piece with the restraining material, the required rigidity is ensured in the connected state. can be obtained.

By controlling changes in the rigidity of variable-rigidity materials used in building frames using computers, etc., it is possible to vary the natural period of the building according to individual seismic characteristics, thereby suppressing large deformations of the building due to resonance phenomena.

By using a computer-based vibration control method, a comfortable living space with no resonance and less shaking can be created.

[Brief explanation of drawings]

1A and 1B are vertical cross-sectional views of a restrained state and a restrained state showing the basic structure of the present invention, respectively, and FIGS. 2A to 2D are a plan view, a front view, and a cross-sectional view of an embodiment of the present invention, respectively. 3 and 4 are longitudinal sectional views showing modified examples of the drive mechanism, and FIGS. 5 a to d are plan views, front views, and sectional views showing other embodiments, and - sectional view, Figure 6 is a front view showing application to a brace, Figures 7 a and b are front views when applied to an axial force column at the bottom of a building, Figures 8 and 9 are axial directions. Figures 10a and 10b are front views showing an example of application to a brace when the rigidity is variable for both tensile force and compressive force. . 1... Variable rigidity material, 1a, 1b... Piece, 2
a, 2b...Locking protrusion, 3...Restraint material, 4...
Connecting material, 5... Bolt, 6... Ball screw, 7
a, 7b...Mounting flange, 8...Motor, 9
a, 9b... Gear, 10... Support stand, 11... Support, 12... Slider, 13... Guide member, 14... Stopper, 15... Bracket,
16... Axial force column, 17... Brace or shear wall, 21... Pin, 22... Restraint material.

Claims (1)

[Claims] 1. An elongated member consisting of two or more pieces,
A building characterized in that one of the opposing pieces is provided with a restraining member that can simultaneously engage and disengage the locking protrusions provided on the opposing connecting ends of the pieces by actuation of a drive device. Variable stiffness material for the frame. 2. The variable rigidity member for a building frame according to claim 1, wherein the locking protrusions are provided on two opposing surfaces of each piece. 3. The variable rigidity member for a building frame according to claim 1 or 2, wherein the restraint member is movable in a direction perpendicular to the axial direction of the piece by the operation of the drive device. 4. The variable building frame according to claim 1, 2 or 3, wherein the ends of the opposing pieces are connected by a connecting member in the axial direction of the piece whose tensile rigidity is sufficiently smaller than that of the piece. Rigid material. 5. The variable rigidity member for a building frame according to claim 4, wherein the connecting member is a steel bar.