JP3366862B2 - Damping structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control structure for suppressing vibration of a structure caused by wind, an earthquake or the like.

[0002]

2. Description of the Related Art Conventionally, as a vibration control structure for suppressing vibration of a structure caused by wind, earthquake, etc.
There is one disclosed in Japanese Patent No. 44356.
This damping structure is a damping structure of a building, and as shown in FIG. 5, a horizontal member made of structural steel is placed inside a frame surrounded by columns 1 and 1 and 2 made of structural steel. A mountain-shaped frame 3 including 4 and inclined members 5 and 5 is arranged, and the beam 2 and the horizontal member 4 of the mountain-shaped frame 3 are connected to each other via a joint member 6.

The joining member 6 in the vibration damping structure is made of low-yield stress steel having an H-shaped cross section as shown in FIG. 5, and against the force received from the beam 2 or the horizontal member 4 of the chevron bridge 3. , Is to be resisted by the shear stress of the web portion 6a. And in case of a big earthquake, the web 6a
It is expected that the seismic energy will be absorbed by yielding and shearing as shown in Fig. 6, resulting in a large damping force.

[0004]

However, the above damping structure has the following problems. That is, as shown in FIG. 7, when a predetermined or more external force (tensile stress) is applied to the steel material, it yields, and a yield region a that easily deforms when an external force is applied for a while continues. Then, when an external force is further applied, it shifts to a strain hardening region b which is not easily deformed even if an external force is applied. FIG. 8 shows a hysteresis curve of displacement and load when a shear load is repeatedly applied to a steel material.
When the strain hardening region b is deformed, a hardening type displacement-load characteristic as shown by a broken line in the drawing is exhibited.

In the above-mentioned damping structure using steel as an earthquake energy absorption damper, the yield region a can be designed easily by modeling the restoring force characteristics of the structural system when performing an earthquake response analysis. It's easy. However, in the strain hardening region b (hardening region), it is difficult to model the restoring force characteristic of the structural system, and the design becomes complicated. Also,
The strain hardening region b is a transient unstable region from the yield region a to the cutting point. Not only that, but a resistance force against an external force is generated, and the resistance force flows to the beam 2 and the chevron bridge 3 forming the structural system. Therefore, there is a problem that the beam 2 and the chevron bridge 3 must be strengthened. Therefore, when designing the vibration damping structure, it is desirable that the deformation region be within the yield region a.

By the way, as shown in FIG.
The web portion 6a in the case where is made of low yield stress steel having an H-shaped cross section is a plate-shaped steel material. Since the skewness of the plate-shaped steel material is inversely proportional to the initial length when no external force acts, the longer the initial length, the more difficult it is to reach the strain hardening region b during an earthquake. However, if the length of the plate-shaped steel material is lengthened in the frame of a fixed size, that is, if the length of the web portion 6a of the low yield stress steel 6 having an H-shaped cross section is lengthened, it is possible to use the mountain frame 3 under. There is a problem that the effective area is reduced and restrictions are imposed when using it as a door or a passage.

Therefore, an object of the present invention is to provide a damping structure in which the deformation region of the joining member does not easily reach the strain hardening region and the opening area of the mountain frame can be made large.

[0008]

In order to achieve the above object, the invention according to claim 1 has a frame body surrounded by two columns made of structural steel and two beams made of structural steel. A mountain-shaped frame having an inclined member made of structural steel and a horizontal member made of structural steel, and the lower end of the inclined member of the mountain-shaped frame is connected to the frame body, while the horizontal member is In a vibration damping structure joined to the upper beam constituting the frame through a joining member made of low-yield stress steel having a lower yield point than steel for use, the joining member has a curved shape, and
It is equipped with a plurality of plate-like parts arranged in parallel in the extending direction of the beam .
The initial length L ₀ of the plate-shaped part of the above-mentioned joining member is outside the design earthquake.
The plate at the time when the frame is maximally deformed by force
If the length of the section is L, the flatness calculated by the following formula
The value of the uniform strain rate ε is determined in the tensile test of the low yield stress steel described above.
It is less than the skewness at the boundary between the yield region and the strain hardening region.
It is characterized by being set as follows. ε = L / L ₀ −1

According to the above structure, the connecting member attached to the horizontal member of the mountain frame installed in the frame body surrounded by the pillar and the beam and the upper beam forming the frame body has a low yield stress. It is made of steel and has a plurality of curved plate-shaped portions. Therefore, when a force is applied to the frame, the opening angle of the curved portion of the plate-shaped portion reduces the tensile force applied to the plate-shaped portion due to the relative displacement of the beam with respect to the horizontal member. Further, since the plate-shaped portion is curved, the initial length of the plate-shaped portion can be increased without widening the distance between the upper beam and the horizontal member, and the degree of strain applied to the plate-shaped portion is reduced. . Therefore, it becomes difficult for the deformation area of the plate-shaped portion to reach the strain hardening area. In that case,
Since it is not necessary to widen the interval between the upper beam and the horizontal member, it is possible to take a large available area under the chevron frame in the frame body.

Furthermore, even if the frame by an outer force is maximum deformation, the deformation area of the plate-like portion does not reach the strain hardening region. Therefore, an effective and stable vibration damping effect can be obtained by the frame body, the chevron frame and the joining member.

According to a second aspect of the invention, in the vibration damping structure of the first aspect of the invention, the joining member functions as a shear plastic damper. There is.

According to the above structure, when a horizontal force is applied to the upper beam and the lower beam which form the frame,
The above-mentioned joining member functions as a shear plastic damper to obtain an effective vibration damping effect.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a diagram showing a vibration damping structure of the present embodiment. In FIG. 1, 11 and 11 are columns made of structural steel, and 12 and 12 are beams made of structural steel. Then, in the frame body surrounded by the columns 11 and 11 and the beams 12 and 12, a chevron frame 13 made of structural steel is arranged. This mountain-shaped frame 13 has two inclined members 14, one end of which is connected to the beam 12 on the lower floor by the bolts or the like at the intersecting position of the pillars 11 and the beam 12 on the lower floor, and which extends toward the center of the beam 12 on the upper floor. 14 and a horizontal member 15 arranged in parallel with the beam 12 and having the other ends of both the inclined members 14 and 14 attached to the center with bolts or the like.

There is a predetermined gap between the beam 12 on the upper floor and the horizontal member 15, and a joining member 16 made of low yield stress steel having a lower yield point than the structural steel is provided at the gap. Three pieces are arranged, and the upper part of each joining member 16 is provided with the beams 13 on the upper floor.
On the other hand, the lower part is fixed to the horizontal member 15.

FIG. 2 shows two members that move in parallel.
A connecting member (joint member 1) for connecting between (corresponding to the beams 12, 12)
(Corresponding to 6) is shown. FIG. 2A shows two members 1
This is a case where the connecting member 19 connecting the 7 and 18 is a flat plate-shaped body. Further, FIG. 2B shows a case where the connecting member 22 that connects the two members 20 and 21 is a curved plate-shaped body.
Now, the connecting member 1 accompanying the relative movement of the member 17 and the member 20.
It is assumed that the deformation amounts of 9 and 22 are the same ΔL. Then, the strain ε1 of the connecting member 19 becomes ε1 = ΔL / L1 (L1 = initial length of the connecting member 19). The strain ε2 of the connecting member 22 is ε2 = ΔL / L2 (L2 = initial length of the connecting member 22)
Becomes Here, since L1 <L2, ε1> ε2. That is, by bending the connecting member to increase the initial length, it is possible to reduce the strain amount of the connecting member with respect to the same amount of deformation without changing the distance between the two members that move in parallel with each other. It is difficult to reach the area.

Therefore, in the present embodiment, as shown in FIG. 3, the joining member 16 is arranged in parallel in the extending direction of the beams 12 and 12 and bent in the same direction in a V shape. A plurality of plate-shaped portions 27, 27, ... Are provided. The plate-shaped portion 27 is formed between each groove 26 by providing a plurality of “V” -shaped grooves 26, 26, ... In parallel to one low-yield stress steel plate 25. When the initial length L ₀ of the plate-shaped portions 27, 27, ... In that case is L when the length of the plate-shaped portion 27 at the time when the frame body is deformed to the maximum by the design earthquake external force is L, The value of ε (= L / L ₀ −1) is set to be equal to or less than the skewness of the boundary between the yield region a and the strain hardening region b shown in FIG. In addition, in the present embodiment, “ku” provided on one low yield stress steel plate 25.
The plate-like portion 27 of the joining member 16 is formed between the plurality of V-shaped grooves 26, 26, ... As shown in FIG.
A plurality of Ms having a web portion 28 that is bent in a "dogleg" shape
It may be configured by arranging low-yield stress steel having a die cross section.

The damping structure having the above structure operates as follows. FIG. 4 shows the state of the vibration control structure during a wind or earthquake. FIG. 4A shows the case of the vibration damping structure in the present embodiment, and FIG. 4B shows the case of the conventional vibration damping structure. When horizontal force acts on the frame during an earthquake, beam 1
Horizontal deformation and rotational deformation occur in the beam 2, and the beam 12 is displaced relative to the horizontal member 15 of the chevron frame 13 as indicated by the broken line. In that case, as shown in FIG. 4A, the joining member 29 is bent in a V shape. Therefore, the relative displacement of the beam 12 with respect to the horizontal member 15 causes the web portion 28 to move.
The tensile stress applied to the initial bending angle θ ₀
It can be relaxed by opening angle.

Further, the web portion 2 of the joining member 29 is used.
The initial length L _{0 of} 8 is the value of the average skewness ε (= L / L ₀ −1), where L is the length of the web portion 28 at the time when the frame body is deformed by the design external force. Yield area a
Is set to be equal to or less than the skewness of the boundary between the strain hardening region b. Therefore, in the event of an earthquake, the deformation area of the web portion 28 does not reach the "strain hardening area b" even if the frame body is deformed, and an effective and stable vibration damping effect can be obtained. .

On the other hand, as shown in FIG. 4 (b), in the conventional joining member 31 made of a plurality of H-shaped low-yield stress steels having a flat plate-shaped web, “2” -shaped web portion 2 like the joining member 29 in the form of FIG.
The effect of absorbing horizontal deformation and rotational deformation due to the opening angle of 8 (releasing effect of horizontal force and rotational force) cannot be expected. Further, the initial length L ₀ '(≈L1) is also short, and when the length of the joint member 31 at the time when the frame is deformed to the maximum by the design earthquake external force is L', the average strain degree ε (= L ' The value of / L ₀ '-1) is not set to be less than the skewness of the boundary between the yield region a and the strain hardening region b. Therefore, in the conventional joining member 31, when the frame body is largely deformed by the force of the design earthquake external force during an earthquake, the deformation region of the joining member 31 reaches the “strain hardening region b”. Therefore, the vibration damping effect cannot be obtained effectively and stably.

As described above, in this embodiment, the chevron frame 13 made of structural steel is arranged in the frame body surrounded by the columns 11, 11 and beams 12, 12 made of structural steel. A plurality of plate-shaped portions 27 are provided between the beams 12 on the upper floor and the horizontal member 15 of the mountain-shaped frame 13 in parallel in the extending direction of the beams 12 and 12, and are bent in the same direction in a V shape. The joining members 16 and 29 having the and 28 are attached. Then, when the initial length L ₀ of the plate-shaped portions 27, 28 is L when the length of the plate-shaped portions 27, 28 at the time when the frame body is deformed to the maximum by the design seismic external force, the average skewness ε ( The value of (= L / L ₀ −1) is set to be equal to or less than the skewness at the boundary between the yield region a and the strain hardening region b.

Therefore, the tensile stress applied to the plate-like portions 27 and 28 due to the relative displacement of the beam 12 with respect to the horizontal member 15 is reduced by the bending angle θ of the "dogleg" -shaped plate-like portions 27 and 28.
It can be relaxed by the opening angle of. Also, the joining members 16, 29
It is possible to prevent the deformation region of (1) from reaching the strain hardening region (b) and obtain an effective and stable vibration damping effect.
The initial length L ₀ of the plate-shaped portions 27 and 28 of the joining members 16 and 29 is determined so that the value of the average strain ε (= L / L ₀ -1) is less than the strain at the boundary between the yield region a and the strain hardening region b. It is possible to set so that even if the plate-like portions 27 and 28 have straight shapes. However, in that case, the joining member 16,
Since the length of 29 in the vertical direction becomes long, the usable area under the mountain frame 13 is reduced accordingly.
That is, according to the present embodiment, the damping structure in which the deformation region of the joining member is hard to reach the strain hardening region at the time of an earthquake,
It can be obtained with a simple structure. Further, the area of the opening in the mountain frame 13 can be made large without impairing the vibration damping effect, and there is no restriction when providing a door or a passage in the opening.

When the bending angle θ of the V-shaped plate-like portions 27 and 28 forming the joining members 16 and 29 is opened, the deformation region of the bending portions of the plate-like portions 27 and 28 is It is possible to enter the hardening area. Therefore, the thickness of the bent portions of the plate-shaped portions 27, 28 may be made thicker than other portions,
It is desirable to make the bending rate of the bent portion smooth.

[0023]

As is apparent from the above, in the damping structure of the invention according to claim 1, the mountain-like frame horizontal member disposed in the frame body surrounded by the columns and the beams is provided above the frame body. The joint member that is coupled to the beam has a curved shape and also has a plurality of plate-shaped portions arranged in parallel in the extending direction of the beam, so that when a force acts on the frame body, The pulling force applied to the plate-shaped portion can be relaxed by the opening angle of the curved portion of the plate-shaped portion. Further, since the plate-shaped portion is curved, the initial length of the plate-shaped portion can be increased without widening the interval between the upper beam and the horizontal member, and the degree of strain applied to the plate-shaped portion can be reduced. Therefore, it is possible to make it difficult for the deformation region of the plate-shaped portion to reach the strain hardening region. In that case, since it is not necessary to widen the interval between the upper beam and the horizontal member, the opening area of the chevron frame in the frame body can be made large, and the restriction when using the opening is eliminated. You can

Furthermore, the initial length of the plate-like portion of the upper Symbol joint member L
₀ means that when the length of the plate portion at the time of maximum deformation of the frame due to the design earthquake external force is L, the value of the average strain degree ε obtained by the following formula is the tensile strength of the low yield stress steel. Since it is set to be less than or equal to the degree of strain of the boundary between the yield region and the strain hardening region in the test, when the frame body is deformed to the maximum by an external force, the deformation region of the plate-shaped portion reaches the strain hardening region. Can be prevented. Therefore, an effective and stable vibration damping effect can be obtained by the frame body, the chevron frame and the joining member. ε = L / L ₀ −1

Further, since the joining member in the damping structure of the invention according to claim 2 functions as a shear plastic damper, the upper beam and the lower beam constituting the frame body are When a horizontal force is applied to the joint member, the joint member functions as a shear plastic damper to obtain an effective vibration damping effect.

[Brief description of drawings]

FIG. 1 is a diagram showing a vibration damping structure of the present invention.

FIG. 2 is a diagram showing a deformed state of a connecting member that connects two members that relatively move in parallel.

FIG. 3 is a diagram showing an example of a joining member in FIG.

FIG. 4 is a diagram showing a deformed state of the vibration control structure during wind or an earthquake.

FIG. 5 is a diagram showing a conventional damping structure.

6 is a diagram showing a state in which the damping structure shown in FIG. 5 is sheared and deformed due to a large earthquake.

FIG. 7 is a diagram showing the skewness-tensile stress characteristics of a steel material.

FIG. 8 is a diagram showing a hysteresis curve of displacement and load when a shear load is repeatedly applied to a steel material.

[Explanation of symbols]

11 ... Pillars, 12 ... Beams, 13 ...
Yamagata frame, 14 ... Inclined member, 15 ...
Horizontal member, 16, 29 ... Joining member,
25 ... Low yield stress steel plate, 26 ... Groove, 27 ...
Plate portion, 28 ... Web portion.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Funayama 2-2-2 Matsuzaki-cho, Abeno-ku, Osaka-shi, Osaka Prefecture Okumura-gumi Co., Ltd. (56) Reference JP-A-10-121772 (JP, A) Flat 2-300475 (JP, A) JP 2-186024 (JP, A) JP 3-144080 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E04H 9 / 02 311 E04H 9/02 321

Claims (2)

(57) [Claims] 1. A tilt member made of structural steel and a horizontal member made of structural steel are provided in a frame body surrounded by two columns made of structural steel and two beams made of structural steel. Arranging a mountain frame having the same, while connecting the lower end of the inclined member of the mountain frame to the frame, the horizontal member through the joining member made of low yield stress steel having a lower yield point than the structural steel. In the vibration damping structure coupled to the upper beam that constitutes the frame body, the joining member has a curved shape, and includes a plurality of plate-shaped portions arranged in parallel in the extending direction of the beam , The initial length L ₀ of the plate-shaped portion of the above-mentioned joining member depends on the design earthquake external force.
Therefore, the plate-shaped portion at the time when the frame body is maximally deformed
When the length of is defined as L, the average strain calculated by the following formula
The value of the degree ε is the yield in the tensile test of the above low yield stress steel.
Keep it below the skewness at the boundary between the yield region and the strain hardening region
A damping structure characterized by being set . ε = L / L ₀ −1 2. The damping structure according to claim 1, wherein the joining member functions as a shear plastic damper.
Damping mass, characterized in that it it.