JP2000170247A - Buckling stiffening member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a buckling stiffening member for reducing member yield strength without reducing rigidity wherever practicable and preventing the whole buckling. SOLUTION: A flat steel serving as a shaft material 2 is inserted in a diagonal layout into a stiffening tube 1 which is an angular steel tube to form this buckling stiffening member. Both faces of the shaft material 2 are pinched by steel sheets 7 with an adhesion preventing agent 7a. The shaft material 2 is partially made smaller in cross section than the other portion to adjust member yield strength. An elliptic hole is formed at the center section of the shaft material 2 to adjust member yield strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brass or truss member used for a building frame structure, in which a rectangular steel pipe as a stiffening pipe is provided in a longitudinal direction of a flat steel as an axial force member. By inserting the joints formed at both ends along the diagonal line of the rectangular steel pipe, and when compressive force is applied to the flat steel, the deformation of the flat steel is restrained at the corners of the rectangular steel pipe. The present invention relates to a buckling stiffening member for preventing buckling.

[0002]

2. Description of the Related Art In order to absorb plastic strain energy while preventing buckling of braces and the like during an earthquake, a flat steel is inserted along a diagonal line into a rectangular steel pipe as a stiffening pipe.
A buckling stiffening member in which joints are formed at both side ends of a flat steel is arranged has been proposed.

As this buckling stiffening member, Japanese Patent Application Laid-Open No. 9-22 / 1997
No. 1830 is disclosed. As shown in FIGS. 40 and 41, a flat steel 2 as a shaft is inserted into a square steel pipe 1 as a stiffening pipe in a diagonal arrangement with a gap α.
When a compressive force is applied to the flat bar 2, the flat bar bends in a direction perpendicular to the material core, and buckling of the flat bar is restrained by the corners of the rectangular steel tube 1 as a stiffening tube. Both ends 3a and 3b of the flat steel projecting from both sides of the rectangular steel pipe 1 serve as joints for attaching the buckling stiffening pipe to a steel column or beam member.

[0004]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 9-22 / 1990
No. 1830 can restrain buckling on the compression side, and thus exhibits excellent hysteretic behavior under repeated loading.

[0005] However, according to the above technique, when the shaft width ratio is large, local buckling occurs between the shaft widths when a compressive force is applied. In addition, when the load bearing capacity of the member is small, it is necessary to reduce the cross section of the shaft, and the cross section of the stiffening tube also decreases according to the shaft. As shown in FIGS. 42 to 45, when a member having such a small cross section is arranged in a building, the slenderness ratio of the member is increased and the whole buckling is likely to occur. Also, the rigidity of the member decreases in proportion to the shaft material cross-sectional area.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a buckling stiffening member which solves the above-mentioned problems, reduces the strength of members without reducing the rigidity as much as possible, and prevents buckling as a whole.

[0007]

SUMMARY OF THE INVENTION The present invention provides the above object,
Achieved by:

The first one is a stiffening tube which is a square steel tube,
A buckling stiffening member in which flat steel as a shaft material is inserted in a diagonal arrangement, wherein both surfaces of the shaft material are sandwiched between steel plates with an antiadhesive agent.

In this buckling stiffening member, both surfaces of the shaft are sandwiched between steel plates with an antiadhesive agent, and a slight gap is provided between both edges of the steel plate with the antiadhesive agent and the inner wall of the stiffening tube. ing. With this configuration, when the shaft width ratio is large, it is possible to prevent local buckling from occurring between the shaft plate widths. The buckling stiffening effect can be exerted even if the gap between them becomes large.

The second one is a stiffening tube which is a square steel tube,
A buckling stiffening member in which a flat steel as a shaft member is inserted in a diagonal arrangement, in which a partial cross section of the shaft member is made smaller than other cross sections and the member strength is adjusted.

In this buckling stiffening member, the proof stress is reduced by reducing the width of a part of the shaft and reducing the cross section of the shaft. The length of the narrowed portion is determined according to the strain level by calculating the strain on the member from the interlayer deformation angle during the earthquake. In this structure, the buckling of the shaft is suppressed at the corners of the square steel pipe, but the part where the shaft width is reduced is
Since it is impossible to restrain at the corners, sandwich both sides with steel plates.
At this time, a slight gap is provided between the steel plate and the inner surface of the square steel pipe.

With this configuration, the stiffness can be slightly increased with respect to the conventional buckling stiffening member having the same strength. Further, buckling can be prevented as a whole, and the member can be lengthened.

The third one is a stiffening tube which is a square steel tube,
A buckling stiffening member in which a flat steel as a shaft member is inserted in a diagonal arrangement and an elliptical hole is formed in the center of the shaft member to adjust the member strength.

In this buckling stiffening member, an elliptical hole (a drilled hole) is formed in the cross section of the shaft to reduce the cross section of the shaft, thereby reducing the proof stress. In this case, the rigidity of the shaft is
As shown in the equation of FIG. 13, even if a hole is made, L ₂ in this equation is L
_Since it is very small as compared to ₁ , the decrease in the rigidity is small, and the rigidity of the member is almost the same as before the hole is formed. Moreover, since the cross-sectional area of the steel pipe does not decrease, the slenderness ratio does not change, so that the entire buckling can be prevented and the member can be made longer than the conventional buckling stiffening member having the same strength.

The fourth one is a buckling stiffening member in which a long hole is formed instead of the elliptical hole formed in the shaft member in the second one.

In this buckling stiffening member, the proof stress is reduced by making an elongated hole in the shaft member cross section to reduce the cross-sectional area of the shaft member. The length of this long hole is determined according to the strain level by calculating the strain on the member from the interlayer deformation angle at the time of the earthquake. Since there is a possibility that the elongated hole of the shaft is twisted during compression, both sides are sandwiched between steel plates. Rigidity can be slightly increased compared to a conventional buckling stiffening member having the same strength. In addition, overall buckling can be prevented,
The member can be lengthened.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

First, the first buckling stiffening member will be described. FIGS. 1 (a) and 1 (b) are a front view and a plan view of a form in which the entire length of both sides of a shaft of a first buckling stiffening member is sandwiched between steel plates with an antiadhesive agent. b) and (c) show FIG.
FIG. 2 is a front view of a buckling stiffening member in which a square steel pipe is externally mounted on a shaft member, and is a cross-sectional view along AA and BB of FIG.

In this example, both sides of the entire length of the shaft member 2 having the viscous body 6 coated on both sides are sandwiched between steel plates 7, 7 coated on the side surfaces of the shaft member with an adhesion preventing agent 7a for preventing adhesion of the viscous body. .
When the square steel pipe 1 is externally mounted on the shaft member 2 sandwiched between steel plates, a design is made such that a gap α is formed between the inner wall of the corner of the square steel pipe and both edges of the shaft member.

FIGS. 3A and 3B and FIGS.
(C) shows a case where the shaft material is formed by flat steel 10 of extremely mild steel for substantially the entire length thereof, as in FIG.
An example is shown in which an anti-adhesive agent 7a is applied to the side surface of a shaft, and the steel plate is sandwiched between the steel plates. Of course, also in this case, the design is made such that a gap α is formed between the inner wall of the corner portion of the rectangular steel pipe and both edges of the shaft.

Next, the second buckling stiffening member will be described. FIG. 5 is a front view of the shaft member of the second buckling stiffening member,
Is a sectional view taken along the line AA in FIG. 5, and FIGS. 7 (a) and 7 (b)
FIG. 8 is a front view and a plan view of a buckling stiffening member in which both sides of a small cross section of a shaft member are sandwiched between steel plates. FIG. 8 is a front view of a buckling stiffening member in which a square steel pipe is provided on the shaft member of FIG. FIG, 9, B ₂ -B ₂ sectional view of FIG. 8, FIG. 10 is a B ₁ -B ₁ sectional view of FIG.

In this example, the width of the central portion 2a of the shaft 1 is made smaller than that of the other portions, and the cross-sectional area thereof is made smaller than that of the other portions. However, the portion 2a with the reduced shaft width cannot be constrained by the corner of the rectangular steel pipe 1. Therefore, as shown in FIG. 7, a plurality of fastening holes 5 to 5 are formed in a portion 2a having a reduced shaft material width.
A viscous body 6 is applied to both surfaces of a as an adhesion preventing material, and is sandwiched between steel plates 7 and 7.

Then, the steel plates on both sides are connected to each other by welding or bolts through holes in the holes 5. This prevents the portion 2a having the reduced shaft width from being locally buckled during compression.

Further, by changing the length of the portion 2a in which the width of the shaft member is reduced, the amount of strain that the member bears can be changed. As can be seen from FIG. 17, the rigidity of the member is inversely proportional to the shaft length / cross-sectional area. Therefore, when the members have the same length, the rigidity also decreases to と when the shaft cross-section becomes １ ／. In the case of this shape, the rigidity of the member does not decrease to て も even if the cross-sectional area of the portion 2a where the shaft material width is reduced becomes １ ／.

With this configuration, the proof stress can be reduced without reducing the overall cross section.
Does not need to be small, and buckling can be prevented as a whole.

The both end portions 3a and 3b of the shaft member 2 protruding from the rectangular steel pipe 1 form joints. Reference numeral 4 denotes a stiffener for reinforcing the sectional strength of the joint.

In the above example, when a part of the shaft is made of extremely mild steel, excellent energy absorption capacity is exhibited during an earthquake. This embodiment will be described below.

FIG. 11 is a front view of an example in which a part of the shaft is made of extremely mild steel, FIG. 12 is a cross-sectional view taken along line C ₁ -C _{1 of} FIG. 11, and FIG.
14A and 14B are a front view and a plan view of an example in which a part of a shaft is made of extremely mild steel, and both sides of a small cross-section are sandwiched between steel plates.
Is a front view of the seat屈補rigid member that the exterior of the square tube to the shaft member 13, 15, C ₃ -C ₃ cross-sectional view of FIG. 14, FIG. 16
FIG. 15 is a sectional view taken along line C ₂ -C _{2 of} FIG. 14.

In this example, a flat steel 2b of ordinary steel and a flat steel 10 of extremely mild steel are welded to each other at a position slightly inside each end of the square steel pipe 1 of the shaft 2. In addition, flat mild steel 1
A portion (small cross section) 10a having a reduced plate width is provided at the center of zero. This small section is similar to the example above,
A viscous body 6 is applied to both sides and sandwiched between steel plates 7,7. When the shaft is inserted into the steel pipe, the beam 7 is fixed to the upper and lower ends of the steel plates 7 to prevent the steel plate 7 from slipping and falling.

Next, the third buckling stiffening member will be described. 18 is a front view of a shaft member of the third buckling stiffening member, FIG. 19 is a sectional view taken along line D1-D1 of FIG. 18, and FIG. 20 is a plan view of a shaft member of the third buckling stiffening member. , FIGS. 21 (a), (b),
(C) is the front view of the 2nd buckling stiffening member which covered the square steel pipe with the shaft, and its D2-D2 sectional view.

In this example, an elliptical hole (including a round hole) 11 is formed at the center of the shaft 2. The elliptical hole is preferably a machined hole to avoid concentration of stress. By doing so, the proof stress can be reduced at the portion where the elliptical hole 11 has been cut off. However, since the cross-section deficient portion is a part of the shaft member, the rigidity of the member is slightly reduced. Therefore,
The proof stress can be reduced without reducing the entire cross section of the shaft. Thereby, it is not necessary to reduce the size of the rectangular steel pipe as the stiffening pipe, and it is also possible to prevent the entire buckling. Note that both end portions 3a and 3b of the shaft member 2 protruding from the square steel pipe 1 are
It becomes a joint. Reference numeral 4 denotes a stiffener for reinforcing the sectional strength of the joint.

In the above example, when a part of the shaft is made of extremely mild steel, excellent energy absorption capacity is exhibited during an earthquake. This embodiment will be described below.

FIG. 22 shows an example in which a part of the shaft is made of extremely mild steel.
FIG. 23 is a front view of FIG.₁-E₁Sectional view, FIG. 24
(A) and (b) show that a part of the shaft is made of extremely mild steel,
Plan view of an example with an elliptical hole in the section and a square steel pipe as the shaft
FIG. 25 is a front view of the outer buckling stiffening member,
E of (b)_Three-E_ThreeFIG. 26 is a sectional view of FIG.
E _Two-E_TwoIt is sectional drawing.

In this example, a flat steel 2a of ordinary steel and a flat steel 10
Are welded to form an elliptical hole 11 at the center in the longitudinal direction of the flat mild steel 10. With this configuration, it is possible to exhibit excellent energy absorption capacity at the time of an earthquake as compared with a case where the entire length of the shaft is made of ordinary steel.

Next, the fourth buckling stiffening member will be described. FIG. 27 is a front view of a shaft member of a fourth buckling stiffening member, FIG. 28 is a cross-sectional view taken along line F1-F1 of FIG.
(B) is a front view and a plan view of a form in which both sides of a long hole of a shaft of a fourth buckling stiffening member are sandwiched between steel plates, and FIG. 30 is a shaft in which both sides of a long hole are sandwiched between steel plates. fourth front seat屈補rigid member diagram that exterior a square tube in wood, FIG. 31, F in FIG. 30 ₃ -
F ₃ cross-sectional view, FIG. 32 is a F ₂ -F ₂ cross-sectional view of FIG. 30.

In this example, an elongated hole 12 is formed in the center of the shaft member 2, and the cross-sectional area is reduced as compared with other portions. The long hole is also preferably a machined hole for the above-mentioned reason. The formation of the elongated holes can reduce the proof stress of the shaft member, and can arbitrarily select the length of the elongated holes 12 to change the amount of strain borne by the member. Since the rigidity of the member is inversely proportional to the shaft length / cross-sectional area, if the cross-sectional area of the shaft is １ ／ for the same length, the rigidity is also １ ／. However, as shown in FIG. 35, even if the cross-sectional area of the cross-section defect part (the elongated hole part) is reduced to １ ／, the rigidity of the member does not decrease to １ ／.

As described above, the shaft 2 having the elongated hole 12
However, when subjected to a compressive force, the shaft is twisted at the twelve elongated holes,
In order to prevent local buckling, as shown in FIGS.
7 to restrain the torsion. In this case, the steel plates on both sides are welded through the top through the hole 5, or
Connect with bolts.

With the above construction, the proof stress can be reduced without reducing the entire cross section of the shaft member, so that it is not necessary to reduce the size of the rectangular steel pipe, and it is also possible to prevent buckling as a whole.

In the above example, when a part of the shaft is made of extremely mild steel, excellent energy absorption capacity is exhibited during an earthquake. This embodiment will be described below.

FIG. 33 is a front view of an example in which a part of the shaft is made of extremely mild steel, FIG. 34 is a sectional view taken along line G ₁ -G ₁ , and FIGS.
(B) is a front view and a plan view of an example in which a part of a shaft is made of extremely mild steel, and an elongated hole formed in the center is sandwiched between steel plates, FIG.
Is a front view of the seat屈補rigid member that the exterior of the square tube to the shaft member of Fig. 35, Fig. 37, G ₃ -G ₃ cross-sectional view, FIG. 38, G ₂
-G ₂ is the sectional view.

In this example, a flat steel 2b of ordinary steel and a flat steel 10
Are welded to form an elongated hole 12 at the center in the longitudinal direction of the flat mild steel 10. A viscous body 6 is provided on both sides around this slot.
And sandwiched between steel plates 7, 7. With this configuration,
Excellent energy absorption capacity at the time of an earthquake can be exhibited as compared with the case where the entire length of the shaft is made of ordinary steel.

[0042]

According to the present invention, buckling stiffening with a shaft member having a large width-to-thickness ratio and buckling stiffening with a large gap between the shaft member and the inner wall of the steel pipe become possible. In addition, since the proof stress can be reduced without reducing the size of the steel pipe, it is possible to prevent buckling as a whole. Furthermore, the length of the member can be increased. Furthermore, by arbitrarily selecting the length of the cross-section defect portion, the strength of the member can be changed while securing the rigidity.

[Brief description of the drawings]

FIG. 1A is a front view of a first buckling stiffening member according to the present invention, in which the entire length of both shafts is sandwiched between steel plates with an antiadhesive agent, and FIG. It is.

2 (a) is a front view of a buckling stiffening member in which a square steel pipe is provided on the shaft member of FIG. 1, (b) is a cross-sectional view taken along line AA of (a),
(C) is BB sectional drawing of (a).

FIG. 3 (a) is a front view of a first buckling stiffening member according to the present invention, in which the shaft is made up of extremely mild steel flat steel substantially the entire length, but both surfaces are sandwiched between steel plates with an antiadhesive agent. , (B) is a plan view thereof.

4 (a) is a front view of a buckling stiffening member in which a square steel pipe is externally mounted on the shaft member of FIG. 3; FIG. 4 (b) is a sectional view taken along line AA of FIG.
(C) is BB sectional drawing of (a).

FIG. 5 is a front view of a shaft member of a second buckling stiffening member according to the present invention.

FIG. 6 is a sectional view taken along line AA of FIG. 1;

FIG. 7A is a front view of a form in which both sides of a small cross section of a shaft member of a second buckling stiffening member are sandwiched between steel plates, and FIG.
Is a plan view of the same.

8 is a front view of a buckling stiffening member in which a square steel pipe is externally mounted on the shaft of FIG. 7;

FIG. 9 is a sectional view taken along line B ₂ -B ₂ of FIG. 8;

FIG. 10 is a sectional view taken along line B ₃ -B _{3 of} FIG.

FIG. 11 is a front view of an example in which a part of the shaft is made of extremely mild steel.

FIG. 12 is a sectional view taken along line C ₁ -C ₁ of FIG. 11;

FIG. 13 (a) is a front view of an example in which a part of a shaft is made of extremely mild steel, and both sides of a small cross section are sandwiched between ordinary steel plates;
Is a plan view of the same.

FIG. 14 is a front view of a buckling stiffening member in which a square steel pipe is externally mounted on the shaft of FIG.

FIG. 15 is a sectional view taken along line D ₃ -D ₃ of FIG. 14;

FIG. 16 is a sectional view taken along line D ₂ -D ₂ of FIG. 14;

FIG. 17 is an explanatory diagram of rigidity of a shaft member.

FIG. 18 is a front view of a shaft member of a third stiffening member according to the present invention.

FIG. 19 is a sectional view taken along line D ₁ -D ₁ of FIG. 18;

FIG. 20 is a front view of a shaft member of a third stiffening member according to the present invention.

[Figure 21] (a) is a front view of a second seat屈補rigid member that the exterior of the square tube to the shaft member, (b), the D ₃ -D
₃ is a cross-sectional view, (c) is out its D ₃ -D ₃ cross-sectional view.

FIG. 22 is a front view of an example in which a part of the shaft is made of extremely mild steel.

FIG. 23 is a sectional view taken along line E ₁ -E ₁ of FIG. 22;

24A is a plan view of an example in which a part of a shaft is made of extremely mild steel and an elliptical hole is formed in the center thereof, and FIG. It is a front view of a stiffening member.

FIG. 25 is a sectional view taken along line E ₃ -E _{3 of} FIG. 24 (b).

FIG. 26 is a sectional view taken along the line E ₂ -E _{2 of} FIG. 20 (b).

FIG. 27 is a front view of a shaft member of a fourth buckling stiffening member.

FIG. 28 is a sectional view taken along line F ₁ -F ₁ of FIG. 27;

FIG. 29A is a front view of a form in which both sides of a long hole of a shaft member of a fourth buckling stiffening member are sandwiched between steel plates, and FIG.
Is a plan view of the same.

FIG. 30 is a front view of a third buckling stiffening member in which a rectangular steel pipe is externally mounted on a shaft having both sides of a long hole portion sandwiched between steel plates.

FIG. 31 is a sectional view taken along line F ₃ -F ₃ of FIG. 30;

FIG. 32 is a sectional view taken along line F ₂ -F ₂ of FIG. 30;

FIG. 33 is a front view of an example in which a part of the shaft is made of extremely mild steel.

FIG. 34 is a sectional view taken along line G ₁ -G ₁ of FIG. 33;

FIG. 35 (a) is a front view of an example in which a part of a shaft is made of extremely mild steel, and a long hole portion opened in the center is sandwiched between steel plates;
(B) is a plan view thereof.

36 is a front view of a buckling stiffening member in which a square steel pipe is externally mounted on the shaft of FIG. 35.

FIG. 37 is a sectional view taken along line G ₃ -G ₃ of FIG. 36;

FIG. 38 is a sectional view taken along line G ₂ -G _{2 in} FIG. 36.

FIG. 39 is a diagram illustrating rigidity of a shaft member.

FIG. 40 is a sectional view of a conventional buckling stiffening member.

FIG. 41 is a view as viewed in the direction of arrows HH in FIG. 40;

FIG. 42 is a front view of a buckling stiffening tube having a small slenderness ratio.

FIG. 43 is a front view of a buckling stiffening tube having a large slenderness ratio.

FIG. 44 is a sectional view taken along the line II of FIG. 42;

FIG. 45 is a sectional view taken along the line JJ of FIG. 42;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stiffened pipe (square steel pipe) 2 Shaft 2a Part with reduced width 2b Flat steel of normal steel 3a, 3b Joint 4 Stiffener 5 Hole 6 Viscous body 7 Steel plate 7a Anti-adhesive agent 8 Beam 10 Flat of extremely mild steel Steel 10a Small cross section 11 Oval hole 12 Long hole

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisaya Kamura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Inside Nihon Kokan Co., Ltd. (72) Inventor Nobuyuki Nakamura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term (reference) in Nippon Kokan Co., Ltd. 2E125 AA01 AA33 AA35 AB16 AC16 AG02 AG03 AG11 AG32 AG43 CA05 2E163 FA01 FB07 FB09 FB23 FB32 FF01

Claims (4)

[Claims] 1. A buckling stiffening member in which flat steel as a shaft is inserted in a diagonal arrangement into a stiffening tube which is a rectangular steel pipe, wherein both surfaces of the shaft are sandwiched between steel plates with an antiadhesive agent. Buckling stiffening member. 2. A buckling stiffening member in which a flat steel as a shaft is inserted in a diagonal arrangement into a stiffening tube which is a square steel pipe, a partial cross section of the shaft is made smaller than the other cross sections to reduce the member strength. A buckling stiffening member characterized by being adjusted. 3. A buckling stiffening member in which a flat steel as a shaft is inserted in a diagonal arrangement into a stiffening tube which is a square steel pipe, an elliptical hole is formed in the center of the shaft, and the member strength is adjusted. A buckling stiffening member, characterized in that: 4. The buckling stiffening member according to claim 3, wherein an elongated hole is formed in place of the elliptical hole formed in the shaft member.