JPH11350778A - Vibration damper and vibration-damping structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration damper capable of being economically manufactured extremely compactly and having extremely large seismic-energy absorption capacity and vibration-damping structure. SOLUTION: Braces 3 are crossed and installed diagonally to a frame consisting of left-right columns 1 and upper-lower beams 2. The vibration damper 4 is mounted at the crossed sections of the braces 3. The vibration damper 4 is formed so that the ratio of a sectional area A1 in the horizontal direction to a sectional area A2 in the vertical direction is equalized to the ratio of the length L of the horizontal component of length S between the supporting points of the braces 3 to the length H of a vertical component. The vibration damper 4 is formed by shaping slits or holes to a steel plate composed of very-low yield-point steel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention attenuates shaking of a building structure by absorbing seismic energy by plastically deforming the building structure when it receives an external force such as an earthquake or a strong wind. It relates to a damping damper and a damping structure.

[0002]

2. Description of the Related Art Hitherto, structural design of main building structures has been performed based on an earthquake-resistant design method. In other words, the structure behaves in the elastic range for frequent medium- and small-scale earthquakes, and plastically deforms to the extent possible while maintaining the yield strength during infrequent earthquakes. This prevents brittle fracture.

[0003] In this way, by giving the structure a large plastic deformation ability, it is possible to prevent the collapse and collapse of the structure due to a large earthquake and to give priority to the protection of human life, and it is inevitable that the structure will be damaged to some extent. I have to.

[0004] However, even for a building structure constructed based on the seismic design method, once it is damaged by a large earthquake, it is extremely difficult to restore the original state, both technically and costly. In many cases, it cannot be expected to be used properly.

[0005] For this reason, recently, especially after the Great Hanshin Earthquake, even if it is damaged by a large earthquake, it is desired that the main structural members such as pillars can be continuously used without any particular repair. There is a strong social demand, technology development is desired, and some have already been put to practical use.

As an example, for example, a vertical load is supported between a foundation and an upper structure constructed on the foundation, but is deformed in a horizontal direction during an earthquake, so that seismic energy is applied to the upper structure. Known is a building having a seismic isolation structure in which transmission is not performed (for example, see Japanese Patent Application Laid-Open No. 8-158).
No. 697).

In addition, during an earthquake, plastic deformation is concentrated on, for example, a lead damper attached separately from the main structural members such as pillars and the like, and the vibration of the structure is reduced by utilizing its hysteresis damping. The quake method is also known (for example, see Japanese Patent Application Laid-Open No. 6-57820).

In particular, in this vibration control method, a buckling restrained brace is attached to a main frame composed of a column and a beam, and the seismic energy is concentrated on the buckling restrained brace to attenuate the seismic energy. Of the main structural members such as pillars and the like are prevented from plasticizing.

The buckling restrained brace used here is formed by filling concrete between a core made of a steel having a yield strength extremely smaller than that of a normal structural steel and a steel pipe installed outside the core. Have been.

Further, as a means for preventing buckling of the compression side brace by the link mechanism, a compression force which causes buckling of the compression side brace is applied by deforming the link member by a tensile force acting on the brace. There is also known one which does not perform such processing (for example, Japanese Patent Laid-Open No. 4-1433).
No. 77).

[0011]

However, seismically isolated buildings have problems such as resonance, which limits the application range, and also causes large deformation between the foundation and the upper structure. Therefore, there is a problem that a lifeline such as water and sewage installed in this portion needs to be installed so as to follow this large deformation.

Further, the vibration control method using the buckling restrained brace has a structure in which the surrounding steel pipe and concrete prevent the buckling of the core material when the buckling restrained brace receives a compressive load. There has been a problem that the member cross section is inevitably large with respect to the cross section dimension of the core material, so that it is difficult to manufacture the core in a functionally compact manner.

[0013] Further, since they are made of different materials such as steel and concrete, there is a problem that cooperation of different kinds of work is unavoidable, so that productivity is low and cost is unavoidable.

Further, the energy absorbing ability of a member receiving an axial force is greater as the portion to be plasticized is longer, but the length of the member is determined solely from the design or functional requirements of the structure to which the member is attached. Because it is
It was extremely difficult in design to obtain the required energy absorption capacity under such conditions.

[0015] In addition, all of the structures tend to be large-scale structures, and are not necessarily sufficient in terms of economy, productivity, workability, and the like.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a vibration damper and a vibration damping structure which can be manufactured extremely compactly and economically and have an extremely large seismic energy absorption capacity. And

[0017]

In order to solve the above problems, a vibration damper according to claim 1 of the present invention comprises:
It is formed so that the ratio between the lengths of the two orthogonal components of the fulcrum length of the braces installed diagonally intersecting with each other and the cross-sectional area ratio of the two orthogonal directions parallel to the two directions are the same. .

[0018] The vibration damper according to the second aspect is the first aspect of the invention.
In the above description, a slit or a hole is formed in a steel plate made of an extremely low yield point steel.

According to a third aspect of the present invention, there is provided a vibration control damper.
In the above description, an anti-buckling flange for restraining out-of-plane deformation is attached around the slit or the hole.

[0020] The vibration damper according to the fourth aspect is the first aspect.
In the description of (2), a buckling prevention frame member that restrains deformation in an out-of-plane direction is attached.

In the vibration damping structure according to a fifth aspect of the present invention, the braces are installed diagonally across a frame composed of left and right columns and upper and lower beams, and at the intersection of the braces. One or more vibration dampers described in 2, 3, or 4 are installed and configured.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention 1 and 2
1 shows an example of a vibration damper and a vibration control structure according to the present invention.
The main frame of the building structure is constructed by the upper and lower beams 2 and 2 bridged between them.

A brace 3 is diagonally crossed and bridged between joints (portions) between the column 1 and the beam 2 which are obliquely opposed to each other, and a vibration damper 4 is provided at the intersection of the brace 3.
Is installed.

Each of the column 1 and the beam 2 is constructed from a shaped steel such as an H-shaped steel, an I-shaped steel, a channel steel, or a rectangular steel pipe, and the brace 3 is a flat steel, a channel steel, an I-shaped steel, or the like. It is formed from a section steel such as an H-section steel or a round steel.

Both ends of the brace 3 are rotatably connected to a joint between the column 1 and the beam 2 via a gusset plate 5. The brace 3 is provided with a turnbuckle 6 for freely adjusting the length so that the brace 3 is not loosened or rattled.

The vibration damper 4 is formed in a rectangular plate shape from extremely low yield point steel such as lead and mild steel. Further, the vibration damper 4 is connected to each brace 3 so as not to rotate via a connection plate 7 such as a feather plate bolt. further,
The vibration damper 4 is connected to the brace 3 so that the material axis of the brace 3 matches.

The vibration damper 4 may be made of ordinary steel as long as its yield point strength is smaller than that of the column 1, the beam 2 and the brace 3. In order to yield before the main structural members and to be able to reliably absorb seismic energy, it is desirable to be formed from extremely low yield point steel.

When the horizontal cross-sectional area of the damping damper 4 in the horizontal direction parallel to the beam axis of the beam 2 is A ₁ and the cross-sectional area in the vertical direction parallel to the beam axis of the column 1 is A ₂ , Area ratio A ₁ :
Length ratio of A ₂ is the length H of the length L and the vertical component of the horizontal component of the fulcrum between the length S of the brace 3 L: as the same as H, and the plate thickness of the Seismic Damper 4 The length of each side is set respectively.

In such a configuration, when a horizontal force P acts on the main frame of the building structure, a tensile force acts on one brace 3 and a compressive force acts on the other brace 3.

Further, since the length of the horizontal component of the length S between the fulcrum points of the brace 3 is L and the length of the vertical component is H, the shear force Q ₁ =
A shear force Q ₂ = P × H / L is generated in the P and vertical directions, respectively.

The sectional area ratio A ₁ : A of the sectional area A _{1 in} the horizontal direction and the sectional area A _{2 in the} vertical direction of the vibration damper 4 is also shown.
₂ is set to be the same as the length ratio L: H of the horizontal component length L and the vertical component length H of the inter-fulcrum length S of the brace 3, so that A ₂ = A ₁ × H. / L.

From the above, A₁Shear stress τ₁
= Q₁/ A₁= P / A₁And A _TwoShear stress τ
_Two= Q_Two/ A_Two= (P × H / L) / (A₁× H / L) =
P / A₁And τ₁= Τ_TwoBecomes

Therefore, since the material of the vibration damper 4 alone is constant, the damper 4 receives the horizontal force P and is simultaneously plasticized in both the horizontal and vertical directions.

If the horizontal and vertical lengths are the same because the horizontal and vertical stresses are constant, the horizontal and vertical directions are deformed by the same amount.

Further, as shown in FIG. 2, the vibration damper 4 is deformed into the shape of a rhombus by the same amount in both the compressing direction and the pulling direction. Deformation follows the deformation, so that the brace 3 on the compression side does not loosen.

FIG. 3 (a) shows the behavior when the main frame, which is merely a diagonally extending brace, receives a horizontal force, and FIG. 3 (b) shows the hysteresis characteristics at that time. .

FIG. 4 (a) shows the behavior when the damper 4 is attached to the intersection of the diagonally crossed braces and the main frame receives horizontal force, and FIG. 4 (b) shows the behavior at that time. It shows a history characteristic.

In FIG. 3A, the main frame is a horizontal force P
, The brace 3a on the compression side has a large slenderness ratio,
Buckles due to low compressive strength. Therefore, the brace 3a cannot follow the deformation of the main frame, and causes excessive bending (slack).

Therefore, the horizontal force P in the opposite direction is applied to the main frame.
Does not act on the brace 3a until the bending is restored, the main frame exhibits a slip-type hysteresis characteristic as shown in FIG.

On the other hand, in FIG. 4A, by installing a vibration damper 4 at the intersection of the brace 3,
Since the buckling due to the compressive force does not occur in the brace 3a, even if the horizontal force P in the opposite direction acts on the main skeleton, the brace 3a is not affected.
Since a tensile force immediately acts on a, the main frame (b) shows a weight-type stable hysteresis curve as shown in the figure, and it can be seen that it has a large damping energy.

Reference numeral 11 denotes a brace connecting hole for connecting the vibration damper 4 and the brace 3 with bolts via the connecting plate 7. Embodiment 2 of the Invention 5 to 8 show other examples of the damping damper and the damping structure according to the present invention. In particular, the horizontal and vertical cross-sectional area ratios A ₁ : A of the damping damper 4 are shown.
₂ is the length L of the horizontal component of the inter-fulcrum length S of the brace 3
In order to make the length ratio L: H equal to the length H of the vertical component, the vibration damper 4 has a plurality of slits or holes 8 formed in a rectangular plate made of extremely low yield point steel such as lead or mild steel. Are formed.

One slit or hole 8 has a square shape at the center, and a plurality of rectangular shapes are formed at predetermined intervals on both left and right and upper and lower sides thereof.

The slit or hole 8 has a sectional area ratio A
_1: A ₂ and a length ratio L: long shape that the H can be set to the same, not necessarily a square shape or a rectangular shape.

The slits or holes 8 are formed by cutting or punching.

According to this example, the vibration damper 4 can be manufactured extremely simply by forming the required number of slits or holes 8 in the steel plate made of extremely low yield point steel.

FIG. 8A particularly shows the shape of the slit or hole 8 formed according to the gradient of the bending moment diagram. That is, when the horizontal force P acts on the slit portion as shown in FIG. 8B, the shearing force Q is constant, but the bending moment M is maximum at the end.

Therefore, the cross-sectional area of the slit end where the maximum bending moment occurs is increased, and the central portion where the bending moment does not occur is minimized. Embodiment 3 of the Invention 9 (a) and 9 (b) and FIG.
(A) and (b) also show another example of the vibration damper according to the present invention, wherein the vibration damper 4 is provided with a plurality of slits or holes 8 in a steel plate made of extremely low yield point steel, and Alternatively, the buckling prevention flange 9 is formed so as to protrude around the hole 8 so as not to buckle in the out-of-plane direction due to a shear force.

The buckling prevention flange 9 is used for forming the slit or hole 8 by cutting or punching.
The slit or hole 8 is formed by, for example, bending the peripheral portion vertically.

The buckling prevention flange 9 is formed by bending the peripheral portion of the slit or the hole 8 alternately on the front side and the back side or only on one side.

As shown in FIGS. 10 (a) and 10 (b), R is provided on the peripheral portion of the slit or hole 8 in accordance with the gradient of the bending moment diagram. It may be formed in an arc shape.

The buckling prevention flange 9 may be formed separately and welded to the periphery of the slit or hole 8 to protrude therefrom. Embodiment 5 of the Invention FIGS. 11 (a) and 11 (b) also show another example of the vibration damper according to the present invention. In particular, the vibration damper 4 is not buckled in the out-of-plane direction due to the shear force.
Buckling prevention frame members 10 for restraining deformation in the out-of-plane direction are attached to both sides of the vibration damper 4.

The buckling prevention frame member 10 has a flange 10a on each of the front side and the back side of the damping damper 4 for restraining the damping damper 4 from being deformed out of plane.
It is formed in a substantially cross shape when viewed from the front.

According to the examples shown in FIGS. 9 to 11, even if the damping damper 4 is made thinner, there is no fear of buckling in the out-of-plane direction. Can be achieved.

In each of the above examples, the case where the vibration damper 4 is installed at the intersection of the brace 3 attached to the main frame composed of the left and right columns and the upper and lower beams has been described. The same effect can be obtained by installing a vibration damper at the intersection of a brace horizontally mounted on a beam frame consisting of a beam and a spanwise beam.

[0055]

The present invention has the above-described structure,
In particular, such that the ratio of the lengths of the two orthogonal components of the length between the fulcrum points of the braces installed diagonally intersecting with each other and the cross-sectional area ratio of the two orthogonal directions parallel to the two directions are the same.
Since the damping damper is formed, even if the damping damper receives compressive and tensile forces simultaneously from two directions via the brace, the amount of deformation of the damper in the two directions becomes the same, and the brace on the compression side The brace on the compression side immediately acts as a tensioner, since no deflection (buckling) occurs.

For this reason, by using the vibration damper, the damping force of the main frame is extremely large, and the shaking of the building structure can be rapidly damped.

Further, since the vibration damper is formed by providing slits or holes in a steel plate made of extremely low yield point steel, the size, shape, number, etc. of the slits or holes are appropriately changed to reduce the brace. The ratio of the lengths of the fulcrum lengths in the two perpendicular directions and the cross-sectional area ratio in the two perpendicular directions parallel to these two directions can be set very easily, making it possible to manufacture a vibration damper extremely easily and at low cost. .

Further, since the buckling prevention flange or buckling prevention frame member for restraining the deformation in the out-of-plane direction is provided, the thickness can be reduced, the weight can be reduced, and the material can be saved.

[Brief description of the drawings]

FIG. 1 is a partial side view of a main frame in which a brace is attached diagonally and a vibration damper is attached to an intersection of the brace.

2A is a front view of a vibration damper, FIG. 2B is a longitudinal sectional view thereof, and FIG. 2C is a transverse sectional view thereof.

FIG. 3A is a diagram showing a behavior when a main frame to which a normal brace is attached diagonally is subjected to a horizontal force,
(B) is a diagram showing the history characteristics.

FIG. 4 (a) is a diagram showing a behavior when a main frame having a diagonally attached brace and a seismic damper attached to the intersection of the brace is subjected to a horizontal force, and FIG. FIG.

FIG. 5 is a partial side view of a main skeleton in which a brace is attached diagonally and a vibration damper is attached to an intersection of the brace.

FIG. 6A is a front view of a vibration damper, FIG. 6B is a longitudinal sectional view thereof, and FIG. 6C is a transverse sectional view thereof.

FIG. 7 is a front view of a vibration damper.

8A is a front view of the vibration damper, and FIG. 8B is a bending moment diagram and a shear force diagram of the slit portion when a horizontal force P acts on the slit portion.

9A is a front view of a vibration damper, and FIG. 9B is a side view thereof.

10A is a front view of a vibration damper, and FIG. 10B is a side view thereof.

11A is a front view of a vibration damper, and FIG. 11B is a side view thereof.

[Explanation of symbols]

 Reference Signs List 1 pillar 2 beam 3 brace 4 damping damper 5 gusset plate 6 turnbuckle 7 connecting plate 8 slit or hole 9 buckling prevention flange 10 buckling prevention frame member 11 brace connection hole

Claims (5)

[Claims] 1. A vibration damper which is installed at an intersection of diagonally intersecting braces and is plastically deformed by an axial force acting on the braces, wherein a right-angle bidirectional component of a length between fulcrums of the braces is provided. A damper characterized in that the ratio of the length and the cross-sectional area ratio in two perpendicular directions parallel to the two directions are formed to be the same. 2. The vibration damper according to claim 1, wherein a slit or a hole is provided in a steel plate made of extremely low yield point steel. 3. The damper according to claim 2, further comprising a buckling prevention flange around the slit or the hole for restraining deformation in an out-of-plane direction. 4. The vibration damper according to claim 1, further comprising a buckling prevention frame member for restraining deformation in an out-of-plane direction. 5. A damper according to claim 1, 2, 3 or 4, wherein a brace is installed diagonally across a frame composed of left and right columns and upper and lower beams, and one of the dampers according to claim 1, 2 or 3 is provided at the intersection of the brace. Or a vibration control structure characterized by the installation of multiple sheets.