JP2000054485A - Haunch plate for jointing column and beam of steel construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a haunch plate for jointing a column and a beam of steel construction, suppressing the generation of cracking and fragile rupture by avoiding stress concentration on a connection part between the haunch plate and a flange, and applicable to steel construction narrow in the depth of the column. SOLUTION: In a haunch plate welded to a column 2 and a H-shape steel beam of steel construction to connect the column and H-shape steel, a joint part to a flange 1a is provided with a parallel part 11 almost equal in thickness to the flange 1a, and a haunch part 12 gradually increased in thickness toward an end 10a jointed to the column 2 is integrally connected to the parallel part 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a haunch plate provided at a joint between a column and a beam having a steel structure to prevent brittle fracture at the joint.

[0002]

2. Description of the Related Art Generally, as a beam in a steel frame structure, an H-beam as shown by reference numeral 1 in FIG. 3 is widely used, and a pair of flanges 1a of the beam 1 is connected to a column 2 at each end. The steel structure is formed by welding.

On the other hand, in such a steel structure, in order to guarantee the plastic deformation capability at the end of the beam 1,
It is necessary to secure a plastic deformation region Z of a certain length at the end of the beam 1 at the time of the maximum proof stress. Such a plasticized region z
Is generally said to be about 1/2 to 1 times as large as the beam. Therefore, assuming a moment distribution having a stress gradient as shown in FIG. 3, if the plastic deformation region Z is secured at the end of the beam 1, the value of the moment at the connection end of the beam 1 becomes the total plastic moment. Α times Mp, and this α
Varies depending on the beam span L, the beam width, the type of steel material, and the like, but usually α ≧ 1.3 is required.

Therefore, conventionally, in order to secure such a plastic deformation region Z, as shown in FIGS. 4A to 4C, the end of the flange 1a of the beam 1 is directed toward the column 2. The trapezoidal haunch plate 3 is gradually widened, and the short side portion of the haunch plate 3 is welded (W) to the edge of the flange 1a, and the long side portion 3a is welded (W) to the column 2. By welding the back surface to the web 1b, the beam 1
And the column 2 are connected to each other, and the cross-sectional area of the connecting portion between the beam 1 and the column 2 is increased to increase the proof stress at the end of the beam 1.

When the beam 1 is an assembling H-beam, the flat steel forming the flange 1a is formed shorter by the length of the haunch plate 3 to secure a mounting space for the haunch plate 3. When the beam 1 is a rolled H-section steel, the end of the flange 1a of the beam 1 is cut and removed by a necessary length to secure a mounting space for the haunch plate 3, and the space is provided in the space. The haunch plate 3 is welded.

[0006]

In the case where such a trapezoidal haunch plate 3 is used to secure the plastic deformation region Z, the haunch plate 3 and the flange 1a are connected to each other. , Will be welded at the short side portion of the haunch plate 3, but the short side portion is
This is a location where the cross-sectional area changes greatly in the length direction of the beam 1 and where the stress is concentrated. In addition, the base material near the welded portion W becomes brittle due to thermal effects during welding. It is conceivable that a crack occurs in the welded portion W between the haunch plate 3 and the flange 1a or a brittle fracture occurs in the welded portion W due to the combined action of the above.

Therefore, the present inventors have previously reported in Japanese Patent Application No. Hei 9-3
No. 42227 proposes a haunch plate that can solve the problems of the above-mentioned conventional haunch plate. This haunch plate is, as shown in FIGS.
A parallel portion 4 having substantially the same width as that of the flange 1a is provided on the side of the H-shaped steel beam 1 to be joined to the flange 1a, and the parallel portion 4 is directed from its end to the steel frame column 2. A haunch portion 5 whose width gradually increases is integrally provided.

According to the haunch plate 6 having the above structure, the joining between the haunch plate 6 and the flange 1a is performed.
Since the process is performed in the parallel portion 4 having substantially the same width as the flange 1a whose sectional shape does not change, the haunch plate 6
The stress concentration at the welded portion W between the welding portion W and the flange 1a can be reduced, so that the occurrence of cracks and brittle fractures at the welded portion W can be suppressed, and the haunch portion 5 connected to the parallel portion 4 Since the width dimension is formed so as to gradually increase toward the column 2, a remarkable effect that the plastic deformation capacity of the beam can be sufficiently secured can be obtained.

However, the conventional haunch plate 3,
6 has a drawback that it cannot be applied to a steel frame structure having a narrow column because the long sides 3a and 6a cannot be wider than the width of the column 2.

SUMMARY OF THE INVENTION The present invention has been made to effectively solve the problems of such a conventional haunch plate for connecting a column and a beam having a steel structure. Therefore, it is possible to suppress the occurrence of cracks and brittle fractures, and to apply it to steel structures with narrower columns.
It is an object of the present invention to provide a beam joining haunch plate.

[0011]

According to a first aspect of the present invention, there is provided a haunch plate for connecting a column and a beam having a steel structure, comprising:
In a haunch plate welded to a flange of a shaped steel beam and connecting these columns and an H-shaped steel beam, a parallel portion having a thickness substantially equal to the thickness of the flange is formed at a joint portion with the flange. And a haunch portion whose thickness dimension gradually increases toward an end portion to be joined to the pillar is integrally connected to the parallel portion.

According to the first aspect of the present invention, the welding between the haunch plate and the flange is performed at the end of the parallel portion provided on the haunch plate and having substantially the same thickness as the flange. In addition, it is possible to eliminate the change in the cross-sectional shape at the welded portion and to reduce the stress concentration at the connection portion between the haunch plate and the flange. As a result, it is possible to suppress the occurrence of cracks and brittle fracture at the connection portion. From such a viewpoint, it is more preferable that the continuous portion of the parallel portion and the haunch portion of the haunch plate is subjected to a rounding process to reduce stress concentration.

[0013] In addition, since the haunch portion extending from the parallel portion to the joint end portion with the column is formed so as to be gradually thicker toward the column, the width of the haunch portion is adjusted to the flange and the flange. Even when formed in the same manner as the parallel portion, the sectional area can be gradually increased toward the column side. As a result, even in a steel frame structure having a narrow column, it is possible to easily obtain the proof stress necessary to secure the plasticized region near the connection end with the column.

[0014]

1 (a) to 1 (c) and FIG.
(A), (b) shows one Embodiment and its modification of the haunch plate for column / beam joining of the steel structure according to the present invention. In FIG. 1, a haunch plate indicated by reference numeral 10 has one end 10a welded to a column 2 and the other end 10b welded to an upper and lower flange 1a of a beam 1 made of H-section steel. , These pillars 2 and H
When a bending moment acts on the beam 1 by connecting the beam 1 with a shape, the plastic deformation area at both ends of the beam 1 is secured to maintain the plastic deformation ability of the beam 1.

Here, the haunch plate 10 is connected to the beam 1
A parallel portion 11 having a plate-shaped member formed of the same material as that of the above, and having a width dimension and a thickness dimension formed at a joint portion with the flange 1a equal to the width and thickness of the flange 1a;
From the parallel portion 11 toward the joint end 10a with the column 2,
A haunch portion 12 having the same width and gradually increasing in thickness is integrally formed. As a result, the cross-sectional area of the haunch portion 12 is
It gradually increases from the first side toward the pillar 2 side.

As shown in FIG. 2A, for example, the parallel portion 11 and the haunch portion 12 increase the thickness of the haunch portion 12 linearly toward the connection end 10a with the column 2 and Alternatively, a rounding process 13 may be applied to the vicinity of the boundary with the parallel portion 11 to reduce the concentration of stress, or the thickness of the entire haunch portion 12 may be parallel as in the modification shown in FIG. It may be formed so as to continuously increase in a concave curve form from the portion 11 side toward the column 2 side.

In order to mount the haunch plate 10 having the above-described configuration, when the beam 1 is an assembled H-section steel, the flat steel forming the flange 1a is formed shorter by the length of the haunch plate 3 to form the flange 1a. A space for mounting the haunch plate 10 is secured. When the beam 1 is a rolled H-section steel, the end of the flange 1a of the beam 1 is cut and removed by a necessary length to secure a space for mounting the haunch plate 10. Then, at the end of the beam 1, the flange 1a
The haunch plate 10 is placed in the space above the web 1b protruding from the end of the
b is welded (W) to the end of the flange 1a, and the end 10a of the haunch portion 12 is welded (W) to the column 2;
Further, the web 1b of the beam 1 is welded to the back surface side to be integrally fixed to the beam 1.

According to the haunch plate 10, the load that causes the haunch plate 10 to undergo plastic deformation acts on the haunch portion 12 from the flange 1a of the beam 1 via the parallel portion 11 of the haunch plate 10. 11 and the haunch portion 12 and the flange 1a are formed to have substantially the same width and thickness, so that there is no change in the area of the stress transmitting surface at the welded portion (W) with the flange 1a, and this welded portion (W) Can be suppressed from being concentrated on the welded portion (W), so that the occurrence of a crack or a brittle fracture in the welded portion (W) can be suppressed. Also, since there is no weld at the boundary between the parallel portion 11 and the haunch portion 12 where the cross-sectional area of the stress transmitting surface changes, and a radius process is applied between them, cracks and brittleness are also generated at the boundary. Breakage can be suppressed.

Further, the haunch portion 12 extending from the parallel portion 11 to the joint end portion 10a with the column 2 is formed so as to be gradually thicker toward the column 2 side. The width of the portion 12 is adjusted by the flange 1a and the parallel portion 11
Even if it is formed in the same manner as above, the cross-sectional area of the haunch plate 10 can be gradually increased toward the column 2 side. As a result, even in a steel structure having a narrow column, the strength required to secure a plasticized region can be easily and reliably obtained in the vicinity of the connection end with the column 2.

[0020]

As described above, according to the first aspect of the present invention, the welding between the haunch plate and the flange of the beam is performed by a parallel welding having substantially the same thickness as the flange provided on the haunch plate. By performing through the portion, the acting stress on the welded portion can be reduced, and the occurrence of cracks and brittle fracture in this welded portion can be suppressed. In addition, the haunch portion from the parallel portion to the joint end portion with the column,
Since it is formed so that it gradually becomes thicker toward the column side,
Even when the width dimension of the haunch portion is the same as that of the flange and the parallel portion, the cross-sectional area can be gradually increased toward the column side, so that even in a steel frame structure having a narrow column width, In the vicinity of the connection end, the strength required to secure the plasticized region can be easily obtained.

[Brief description of the drawings]

1A and 1B show an embodiment of a haunch plate for joining a column and a beam having a steel structure according to the present invention, wherein FIG. 1A is a plan view and FIG.
Is a front view, and (c) is a side sectional view.

2A is a side view showing a shape of the haunch plate shown in FIG. 1, and FIG. 2B is a side view showing a modified example thereof.

FIG. 3 is a distribution diagram of a bending moment of a beam at the time of a general steel structure and its maximum strength.

FIGS. 4A and 4B show an example of a conventional column / beam joining haunch plate having a steel structure, wherein FIG. 4A is a plan view, FIG. 4B is a front view, and FIG.

FIG. 5 shows another conventional haunch plate.
(A) is a plan view, (b) is a front view, and (c) is a side sectional view.

[Explanation of symbols]

 Reference Signs List 1 beam 1a flange 1b web 2 pillar 10 haunch plate 10a pillar-side connection end 10b beam-side connection end 11 parallel part 12 haunch part

Claims (1)

[Claims] 1. A haunch plate which is welded to a steel-structured column and a flange of an H-shaped steel beam and connects the column and the H-shaped steel beam, wherein a thickness dimension is formed at a joint portion with the flange. A parallel portion substantially equal to the thickness of the flange is provided, and a haunch portion whose thickness gradually increases toward an end portion to be joined to the pillar is integrally provided on the parallel portion. Haunch plate for column / beam joining of steel structures.