JPH10317711A - Vibration damping brace structure of steel frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exhibit a hysteresis damping effect early even if the horizontal external force is input to a steel frame by an earthquake or the like, and further to keep the stable yield strength of the steel frame. SOLUTION: A brace material 10 formed of a general building steel material is put in the connecting state in a steel frame 6 where steel posts of a rigid frame structure and steel beams are framed. The upper end of the brace material 10 is connected to the upper steel skelton beam. The lower end of the brace material 10 is connected to the steel post 2 and the lower steel beam through a connecting member 14 and a damping member 12. The damping member 12 uses extra mild steel which is plastic-deformed by shearing or bending less than the buckling yield stress of the brace material 10 as material, and is formed as a long panel body. The damping member 12 is connected to the other end of the brace material 10 in such a manner as to intersect perpendicularly thereto through the connecting member 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control brace structure for a steel frame in which a brace is connected to a steel frame.

[0002]

2. Description of the Related Art FIG. 3 shows an H-shaped steel column 2,
1 shows a steel frame 6 having a steel beam 4 as a frame.
The steel frame 6 is provided with two brace members 8 made of H-shaped steel. Each of the brace members 8 has one end fixed to the upper steel beam 4 and the other end connected to the lower steel column 2. And is fixed to the intersection of the steel beams 4. When a horizontal force such as an earthquake is input to the frame 6, the compression reaction force of the two brace members 8 is obtained.
The steel frame 6 is reinforced by a tensile reaction force to improve rigidity and proof stress.

[0003]

Here, as shown in FIG. 4, a horizontal external force F such that the compressive / tensile force acting on the brace member 8 stays below the buckling resistance is applied to the steel frame 6 having the above structure.
_{When 1} acts, little damping occurs.
That is, as shown in FIG. 5, since the brace member 8 is elastically deformed, the hysteresis damping action due to plastic deformation does not occur. On the other hand, as shown in FIG. 6, the brace member 8 acts horizontal external force F ₂ as buckled, with yield strength of steel frames 6 with the buckling of the brace member 8 is lowered, as shown in FIG. 7 not This results in stable hysteresis characteristics.

In view of the foregoing, the present invention has been made in view of the above circumstances, and has an effect of improving the hysteretic energy absorbing ability to produce a vibration damping effect, effectively preventing buckling destruction, and improving the stable strength of a steel frame. It is an object of the present invention to provide a damping brace structure of a steel frame that can be held.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the invention according to claim 1 provides a brace material made of a general building steel material in a steel frame having a steel frame and a steel beam having a rigid frame structure. In the structure, the one end of the brace material is connected to a part of the steel frame, and the other end of the brace material is connected via a vibration damping member that is plastically deformed at a buckling strength or less of the brace material. It was connected to other parts of the steel frame.

According to a second aspect of the present invention, in the vibration damping brace structure for a steel frame according to the first aspect, the damping member is made of a very mild steel having a very low yield point and a very low tensile strength as compared with the brace material. Is composed of a long panel body, and the other end of the brace material is connected to the longitudinal center of the vibration damping member so as to be orthogonal to the brace material, and both ends in the longitudinal direction of the vibration damping member The part was connected to the steel column and the steel beam.

[0007] Further, the invention according to claim 3 is based on claim 2.
In the vibration damping brace structure of a steel frame described above, the other end of the brace material and a connecting portion between the vibration damping members are detachably connected by a bolt connection via a connecting member, and a longitudinal direction of the vibration damping member is provided. And the connecting portions between the steel columns and the steel beams were detachably connected by bolt joining.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. The same components as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 shows a steel frame 6 including two brace members 10 and a vibration damping member 12 connected to one end of the brace members 10. Two braces 1
Numeral 0 is arranged in a K-shape in the steel frame 6, and is made of an H-shaped steel made of a general building steel material (SM490, SS400, etc.). And each brace material 10
Has an upper end fixed to the upper steel beam 4 and a lower end fixed to the steel column 2 and the lower steel beam 4 via the connecting member 14 and the vibration damping member 12.

The vibration damping member 12 has a yield point lower than that of the brace material 10 by about 1/3, a tensile strength lower by about 2/3, and an elongation ratio of the brace material 10 of about 2/3.
It is made of extremely mild steel, which has twice the mechanical properties, and is formed as a rectangular plate-like panel body.

An end of a connecting member 14 made of a general building steel is fixed to a central portion of the damping member 12 in the longitudinal direction so as to extend perpendicular to the longitudinal direction of the damping member 12. ing. The other end 14a of the connecting member 14 is
It is detachably connected to the lower end of the brace material 10 by high-strength bolt joints. Both ends in the longitudinal direction of the damping member 12 extending to the steel column 2 and the lower steel beam 4 are connected to the steel column 2 and the lower steel beam 4 by high-strength bolt joints.

According to the steel frame 6 of the present embodiment, when a compressive / tensile force exceeding the yield strength is applied to the damping member 12 made of extremely mild steel by the horizontal external force due to an earthquake or the like on the steel frame 6, the vibration damping is performed. The member 12 is plastically deformed by shearing or bending, and a hysteresis damping action occurs. Since ultra-mild steel yields with a smaller stress (small strain) than ordinary steel, the yield strength of the damping member 12 can be reduced, and the damping member 12 can be formed from an early stage such that the brace material and the beam-column framework remain in the elastic range. Is plastically deformed. That is, it is possible to cause the hysteresis damping action to occur from an early stage.

Further, by making the maximum proof stress of the vibration damping member 12 lower than the buckling strength of the brace material 10, the compressive force acting on the brace material 10 is suppressed lower than the buckling strength of the brace material 10. Prevent buckling. And
As shown in FIG. 2, even when compressive / tensile forces exceeding the yield strength of the damping member 12 repeatedly act on the brace material 10 and the horizontal displacement increases, the brace material 10 does not buckle, so that the steel frame 6 is stable. It is possible to maintain the proof stress and hysteresis energy absorption capacity.

As described above, by the stable absorption of hysteresis energy of the extremely mild steel portion of the vibration damping member 12 and the effect of preventing the buckling of the brace material 10, the steel frame 6 can improve the vibration damping effect while maintaining a sufficient strength. Can be.

Further, the vibration damping member 12 includes the brace material 10.
Is connected to the lower end of the steel column 2 by a high-strength bolt joint via a connecting member 14 and is connected to the steel column 2 and the lower steel beam 4 by a high-strength bolt joint. It will be easier.

In this embodiment, the two brace members 10 are arranged in a K-shape in the steel frame 6, but the same applies when the V-shaped and X-type brace members 10 are arranged in the steel frame 6. The operation and effect can be obtained.

[0017]

As described above, according to the first aspect of the present invention, since the other end of the brace member is connected to the vibration-damping member which is plastically deformed below the buckling strength of the brace member, However, when a horizontal external force due to an earthquake is input to the steel frame and a compressive / tensile force greater than the yield strength acts on the damping member, the hysteresis damping action occurs early due to plastic deformation of the damping member. Further, by suppressing the maximum proof stress of the damping member to be lower than the buckling proof strength of the brace material, buckling of the brace material can be prevented. Then, even if the compressive force and the tensile force repeatedly act on the brace material to increase the horizontal displacement, the brace material does not buckle, so that the steel frame can maintain a stable strength.

According to the second aspect of the present invention, the effect of the first aspect can be obtained, and the vibration damping member is a long panel body of extremely mild steel and is orthogonal to the brace material. Therefore, the buckling of the brace material can be reliably prevented by suppressing the maximum proof stress of the vibration damping member to be lower than the buckling proof strength of the brace material.
In addition, the long panel body of extremely mild steel yields plastic deformation by yielding with a horizontal external force that keeps the brace material and beam-column framework within the elastic range. The prevention effect can be obtained.

Further, according to the third aspect of the invention, the effect of the second aspect can be obtained, and the other end of the brace material and the connecting portion between the vibration damping members are connected by bolts via the connecting member. Detachably connected by, the longitudinal ends of the damping member, the connection between the steel column and the steel beam,
Since it is detachably connected by bolting, even if the damping member is broken, the work of replacing the damping member with a new damping member becomes easy.

[Brief description of the drawings]

FIG. 1 is a diagram showing a vibration-damping brace structure of a steel frame according to the present invention.

FIG. 2 is a diagram showing a relationship between a horizontal force and a horizontal displacement of a steel frame according to the present invention.

FIG. 3 is a diagram showing a conventional vibration-damping brace structure of a steel frame.

FIG. 4 is a diagram showing behavior of an elastic range of the steel frame shown in FIG. 3;

FIG. 5 is a diagram showing horizontal force and horizontal displacement in an elastic range of a steel frame as shown in FIG. 4;

FIG. 6 is a view showing the behavior of the steel frame when the brace material buckles in the steel frame shown in FIG. 3;

FIG. 7 is a view showing horizontal force and horizontal displacement of the steel frame when the brace material buckles as in FIG. 6;

[Explanation of symbols]

 Reference Signs List 2 steel column 4 steel beam 6 steel frame 10 brace material 12 damping member 14 connecting member 14a end of connecting member 14

Claims (3)

[Claims] 1. A structure in which a brace material made of a general building steel is connected to a steel frame having a steel frame and a steel beam having a rigid frame structure, wherein one end of the brace material is partially connected to the steel frame. And the other end of the brace material is connected to another portion of the steel frame via a vibration damping member that is plastically deformed at a buckling strength or less of the brace material. Damping brace structure. 2. The vibration-damping member is composed of a long panel made of extremely mild steel having a yield point and a tensile strength extremely lower than those of the brace material, and the other end of the brace material has a brace. The longitudinal center part of the damping member is connected so as to be orthogonal to the material, and both ends in the longitudinal direction of the damping member are connected to the steel columns and the steel beams. Damping brace structure of steel frame. 3. A connecting portion between the other end of the brace material and the vibration damping member is detachably connected by a bolt connection via a connecting member, and both ends in a longitudinal direction of the vibration damping member; 3. The connecting part between the steel column and the steel beam is detachably connected by bolt connection.
The damping brace structure of the steel frame described.