JPH0515851B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a variable stiffness material used in a building frame with a vibration damping structure, in which a pin joint provided in a structural member is divided into a pin joint and a rigid joint. convertible,
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, the applicant proposed that instead of using the above-mentioned passive seismic resistance method, the rigidity of the building itself was changed based on the judgment of a response prediction system based on the detected seismic motion, and the We provide a vibration damping method that ensures the safety of buildings, equipment inside buildings, occupants, etc. by setting the vibration outside the area or in a state 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. 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 its frequency characteristics, and predicts the amount of response, and then determines whether or not the building's vibration should be controlled, and if so, the amount of control.
The decision is made as to provide the optimum stiffness (natural frequency) that avoids resonance and reduces the 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, beams, etc. in the above-mentioned vibration damping method, so that the rigidity can be changed to cope with earthquakes and the like. Note that the present invention is not limited to use in the above-mentioned vibration damping method, but can also be used to improve the above-mentioned method, or simply to change rigidity.

[Structure of the invention]

As shown in FIGS. 1a, b, and c, the variable rigidity material of the present invention has a joint 2 that can be converted into a pin joint and a rigid joint in a long structural member consisting of two or more pieces 1a and 1b. It was established. The pin joint part 2, which serves as the fulcrum of rotation, is fixed by a restraint member 3, and the restraint member 3, which connects the two pieces 1a and 1b joined via the pin joint part 2, is movable between a restraint state and a restraint release state. , This allows conversion between pin joints and rigid joints. The drive device for moving the restraining material 3 may be any one of a hydraulic cylinder, an electric type, an electromagnetic type, etc.

In addition, in a member with a three-pin structure that cannot resist compressive force, a restraining material is provided at the central pin joint,
If it can be converted into a pin joint or a rigid joint, it can become a compression resistant material or a non-resistance material by placing it in a restrained state or a restrained state as necessary.

Also, in the pin joint part 2, one piece 1
By providing the locking arm 4 from a to the other piece 1b, the rotation direction at the pin joint can be limited, and there is no space between the locking arm 4 and the other piece 1b. A restraining member 3 may be provided.

Such exchange between pin joints and rigid joints can be performed by a computer control program. In other words, it is possible to control the rigidity of a building using a computer in response to external vibrational forces such as earthquakes, by changing the rigidity and connection state of members in each part of the building, and changing the natural period of the building as a whole. It can also avoid resonance.

〔Example〕

Next, the illustrated embodiment will be described.

Figures 2a to 2e are pin joint parts 2 in one embodiment.
This shows the vicinity of .

Two pieces 1a and 1b are connected by a pin joint 2, and a locking arm 4 extending from one piece 1a toward the other piece 1b connects the pin joint 2.
The direction of rotation is limited. A restraining member 3 is attached to the locking arm portion 4 by a hinge 5 in a direction perpendicular to the axial direction of the variable rigidity member 1 so as to sandwich the other piece 1b. There is a locking protrusion 6 at the tip of the restraint material 3, and the rotation of the restraint material 3 on the hinge 5 allows the mating piece 1b to be grasped or released, thereby allowing pin joints and rigid joints. It can be converted to .

Since the restraint member 3 is subjected to a force that is the sum of the shear force of the variable rigidity member 1 as a structural member and the lever reaction force generated in the restrained state, it is necessary to be able to resist this force. This also applies to the hinge 5 as a pin mechanism of the restraining member 3.

When the force applied to the restraint material 3 is small, instead of the bearing pressure resistance of the locking protrusion 6 of the restraint material 3, as shown in FIG. 3, friction at the contact surface between the restraint material 3 and the other piece 1b The resistance may be caused by a force, or by a magnet 9 attached to the restraining member 3 or the opposing piece 1b as shown in FIG.

As shown in the figure, the rotation of the restraining member 3 can be automatically controlled by a simple actuator such as an electric servo motor 7 provided on the other piece 1b. If the connecting member 8 connecting the restraining member 3 and the servo motor 7 is made of a rigid material such as a steel bar, collision between the restraining member 3 and the opposing piece 1b can be prevented. For this reason,
The joints between the connecting member 8, the restraining member 3, and the servo motor 7 are pin joints so that they can follow the movement of the servo motor 7, and can also be made into universal joints if necessary. In addition, when the connecting member 8 is made of a string-like soft material that cannot resist compression, a cushioning material is provided between the restraining member 3 and the mating piece 1b to reduce the impact.

The power of the servo motor 7 as an actuator only needs to be capable of rotating the restraining member 3 when the locking protrusion 6 and the magnet 9 are provided. Furthermore, if friction is used to provide resistance, sufficient power is required to generate the necessary frictional force. Conversely, if the torque of the servo motor 7 is large, it can be resisted by frictional force as shown in FIG.

Also, contrary to the above configuration, the opponent piece 1
b may be provided with a restraining member, and the locking arm portion 4 may be provided with a servo motor. In addition, opposing restraining materials 3
It is also possible to connect them with a hydraulic cylinder or the like, and expand and contract the hydraulic cylinder to open and close the restraining material.

The point at which the restraining member 3 operates is when the locking arm 4 and the other piece 1b come into contact, that is, when the two pieces 1a and 1b separated through the pin joint 2 become in a straight line. Due to this, vibration etc.
Even parts that are constantly in motion can be converted into pin connections and rigid connections. Note that the maximum amount of rotation in the pin joint 2 is such that the deformation of the building is within permissible limits.

The variable rigidity material 1 can be installed in members such as columns, beams, braces, etc. until the structure becomes unstable when all the variable joints are pin-jointed. By adjusting the number and position of pin joints and rigid joints within this range, the bending rigidity of the member can be changed. Note that if a certain member is not made to resist axial force, one of the fixed pin joints may be made into a loose hole.

Furthermore, if it is used to change the resistance mechanism of a beam or column (including moment columns) against horizontal loads, the rigidity of the member can be controlled. Therefore, even when the frequency characteristics are uncertain, such as earthquakes, it is possible to prevent the building from resonating by changing the rigidity from time to time under computer control.

If there is a locking arm 4, the direction of rotation is limited, so a pair of locking arms 4 that can change in opposite directions is used in response to repeated loads such as earthquakes.

Figures 5a to 5c show variations of the mechanical mechanism for horizontal loads when the variable stiffness material of the present invention is used for beams or columns of rigid frame structures.
Figure a shows a state in which both the pin joints 2 at the two ends of the material are restrained, creating a rigid connection. Figure b shows a state in which one of the pin joints 2 is released and only one is joined with a pin. Figure c shows a state in which both are restrained. This is the case where it is released and a pin connection is made.

6a to 6f similarly show variations of the mechanical mechanism for vertical loads of a beam in which pin joints are provided at a total of three locations, at the ends of both members and at the center.

Figures 7a to 7d show an example of application to a moment column on the lowest floor of a building, using a variable rigidity member 1 with pin joints 2 at the upper and lower ends that can be restrained by restraints 3. ing. Note that the upper pin joint portion 2 has a structure in which the loose hole 10 does not resist axial force. Figures b to d in the same figure are bending moment diagrams. Figure b is when both of the wires are restrained, Figure c is when the upper and lower restraints are released for one wire, and Figure d is when only the upper restraint is released for one wire. This is a case of soft resistance.

8a to 8c show examples of application of the variable rigidity material 1 of the present invention, in which a restraining member 3 is provided at the central pin joint part 2 of a member with a 3-pin structure, enabling switching between restraint and non-restraint, and as required. Depending on the situation, the variable rigidity material 1 is used as a compression resistance material or as a non-resistance material. One piece 1 is attached to the central pin joint 2.
A locking arm 4 is extended from a to the other piece 1b so that it rotates only in one direction when a compressive force is applied when there is no compression resistance. At this time, the locking arm 4 is
A weak spring 11 is provided at the tip of the piece 1b, which is weak enough to push out the other piece 1b in the rotational direction.
The restraint material 3 only needs to have a relatively small cross section that can withstand buckling when the variable rigidity material 1 is used as a compression resistance material. It can be used for braces, pillars for the legs of seismic walls, etc. to vary the rigidity of building frames.

Fig. 9 shows a structure used as a brace for a building frame, in which a variable rigidity member 1 is arranged diagonally in the area surrounded by columns 12 and beams 13, and pins 14 are attached at both ends to the column-beam joints.
It is installed with. The central pin joint portion 2 is variable between a pin joint and a rigid joint, and the pin joint does not resist compressive force in the axial direction, and the rigid joint allows it to resist compressive force.

Figures 10a and 10b are examples of the lowest floor of a building, where variable-rigidity members 1 with a 3-pin structure are arranged as earthquake columns on both sides of the central long-term load column 15. The rigidity of the building is changed by restraining or releasing the pin joint part 2 of the building. 1 in the diagram
6 is a brace or a shear wall.

[Effects of the Invention] By making the pin joint part in the member variable between the restrained state and the restrained state by the restraining material, the pin joint part can be freely converted between pin joint and rigid joint, and the member The stiffness of can be changed.

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.

Apart from the need for restraints and drive devices, building safety can be improved without requiring a particularly large cross section.

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]

Figures 1a, b, and c are a front view, a sectional view in a restrained state, and a sectional view in a released state, respectively, showing the basic structure of the present invention, and Figures 2 a to e are a front view and a restraint of one embodiment, respectively. A cross-sectional view of the state, its plan view,
Cross-sectional view and plan view of restraint release state, 3rd
Figures 5 and 4 are cross-sectional views showing modified examples of the restraining means, Figures 5 a to c and Figures 6 a to f are explanatory diagrams showing changes in the dynamic mechanism in use, and Figure 7 a is a moment column. A front view showing an example of application to
Figures 7b-d are bending moment diagrams, Figures 8a-c
is a front view showing an example of application to a 3-pin structure, FIG. 9 is a front view showing an example of application to a brace, and FIGS.
b is a front view when applied to an axial force column at the lower end of a building. 1... Variable rigidity material, 1a, 1b... Piece, 2
... Pin joint, 3 ... Restraining material, 4 ... Locking arm, 5 ... Hinge, 6 ... Locking protrusion, 7 ... Servo motor, 8 ... Connecting material, 9 ... Magnet, 10...
Loose hole, 11... Spring, 12... Pillar, 13
... Beam, 14 ... Pin, 15 ... Long-term load column,
16...Brace or shear wall.

Claims (1)

[Claims] 1 It is a long member in which two or more pieces are joined via a pin that serves as a fulcrum of rotation, and one piece has a restraining material for restraining the rotation of the other piece, and the restraining material is in a restrained state and released from restraint. A drive device is provided for movable between states, one piece is provided with a locking arm for limiting the direction of rotation of the other piece, and the restraint member has a variable rigidity on the arm. 1. A variable rigidity member for a building frame, comprising a pair of clamping members attached perpendicularly to the member and opened and closed by a drive device to release and restrain the other piece.