JP2020023785A - Scallop and beam end field joint using the same - Google Patents

Abstract

To provide a scallop and a beam end field joint which inhibit strain concentration from occurring at a bottom of the scallop and inhibit occurrence of a scallop bottom crack and a flange fracture without requiring any other structure for reinforcement.SOLUTION: A scallop 60 includes: a first opening end 60a; a second opening end 60b; and a first opening edge part 61 extending in a direction away from a web end from the first opening end 60a; a second opening edge part 62 extending in the aforementioned direction from the second opening end 60b; and a third opening edge part 63 connecting the first opening edge 61 and the second opening edge part 62. The first opening edge part 61 is formed in a circular arc shape intersecting a web 10 side weld toe part of a fillet part 30, and has a first circular arc part 71 having a tangent parallel to an inner surface of a lower flange 20 at one end on the first opening end 60a side. The third opening edge part 63 has a second circular arc part 72 formed in a circular arc shape connecting the first opening edge part 61 and the second opening edge part 62. A radius of curvature of the first circular arc part 71 is larger than the radius of curvature of the second circular arc part 72.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a scallops provided at an end of a web of an H-shaped beam to form a beam end joint of an H-shaped beam, and a beam end in-situ joint using scallops.

  BACKGROUND ART In a steel building in which beams, columns, and the like are formed of steel members, beams and columns may be joined at a construction site during construction. In particular, in the case of an H-section beam using an H-section member as a beam, the ends of the web of the H-section beam and the columns are welded or bolted at a construction site, and the ends of the upper and lower flanges of the H-section beam are connected. Beam-to-column joints, in which a beam and a column are welded at a construction site, are widely and generally employed. At this time, in order to perform welding between the end of the lower flange of the H-shaped section beam and the column, a welding hole usually called scalloped is provided at the end of the web of the H-shaped section beam. The scallops are formed by partially notching the end of the web of the H-shaped beam in the vicinity of the lower flange of the H-shaped beam, and the welding portion between the lower flange of the H-shaped beam and the column passes through the scallops. It is formed across the web of the H-shaped beam.

  The H-section members used for the above-mentioned H-section beams include a welded H-section and a rolled H-section steel. The welded H-shaped cross section is formed by welding portions where a pair of upper and lower flanges and a web intersect each other. Therefore, a fillet formed by welding metal so as to be wider in the thickness direction of the web is provided at a portion where the pair of upper and lower flanges and the web intersect each other. Further, the rolled H-section steel is integrally formed by rolling into an H-shaped cross section including a pair of upper and lower flanges and a web. At this time, a fillet portion called a normal fillet portion formed so as to be wider in the thickness direction of the web is provided at a portion where the pair of upper and lower flanges and the web intersect each other.

  By the way, in the above-mentioned beam end site joint, there is a possibility that the lower flange of the H-shaped section beam may be broken at the time of an earthquake due to concentration of strain on the scallop, and measures to prevent this are required. For this reason, conventionally, measures have been taken to reinforce the scallop and the shape of the scallop, which can reduce the concentration of strain on the scallop.

  For example, in Non-Patent Document 1, as a shape of a scallop capable of alleviating the concentration of strain on the scallop, the scallop has a shape in which two arcs of curvature are combined, and the radius of curvature of the arc connected to the flange is A composite circular scallops having a shape of 10 mm and a radius of curvature of an arc at a portion away from the flange of 35 mm is disclosed. Further, in Non-Patent Document 1, as a scallop shape capable of alleviating the concentration of strain on the scallop, the radius of curvature of a 1/4 circular arc at a portion connected to a flange is set to 10 mm, and the radius of the arc is perpendicular to the arc. An improved B-shaped scallop having a shape having an extending straight portion is disclosed. In Non-Patent Documents 2 and 3, as a shape of a scallop capable of reducing the concentration of strain on the scallop, an arcuate portion and a straight line extending from the arcuate portion are connected to a flange. A scalloped shape is disclosed.

On the other hand, in Patent Document 1, as a measure to reinforce scallop, a steel column beam flange welded joint is formed by a groove comprising a beam flange, a plate-like member joined to the outside of the flange, and a through diaphragm of the steel column. A structure is disclosed in which a joint is formed by completely penetrating and welding a portion, a plate-like member is a tapered plate that linearly decreases in thickness from a thick portion to a thin portion, and scallops are provided on a web of a beam.
Patent Document 2 discloses a structure in which scallops are filled by welding or the like as a measure for reinforcing scallops.

JP 2013-7194 A JP-A-2005-224427

Architectural Institute of Japan: Guideline for Steel Construction Technology, Factory Production, Japan, February 15, 2007, 5th edition, p. 208-211 Tadao Nakagomi, Tetsuya Fujita: Mechanical performance of end of rolled H-shaped steel beam welded and connected in diaphragm form through square steel tubular column Influence of presence or absence of beam scallop and shape and misalignment on fracture properties, Architectural Institute of Japan Transactions No. 455, January 1994, p. 187-196 J. M. Rices, J.A. W. Fisher, Le-Wu Lu, E .; J. Kaufmann; Development of improved welded connection connections for early quake-resistant design, Journal of Construction, Steel Research, No. 2, 200, Research, 200. 565-604

However, scallops as described in Non-Patent Documents 1 to 3 have a problem in that strain is concentrated near a portion where the scallop is connected to the lower flange of the H-shaped beam, usually called a scallop bottom. That is, there is a problem in that the strain is concentrated on the scalloped bottom and a crack is generated in this portion at the time of the earthquake, and the crack propagates to the outer surface of the lower flange of the H-shaped section beam. When this crack propagates to the outer surface of the lower flange of the H-shaped section beam, the lower flange of the H-shaped section beam is broken starting from the crack, which may impair the seismic performance of the steel building. For this reason, a shape of a scallop capable of alleviating the concentration of strain on the scallop bottom is now widely demanded. In addition, when a crack is generated in this part during an earthquake due to concentration of strain on the scallop bottom, it is difficult to visually recognize the generated crack because there is another steel material such as a column to which the H-shaped beam is joined. However, there is a problem that it is difficult to diagnose damage after an earthquake.
Further, in the structure as in Patent Literature 1, it is possible to reduce the stress at the end of the beam, but there is a problem that it takes time to prepare and connect a tapered plate for reinforcement. Similarly, there is a problem in that the structure as in Patent Document 2 requires time and effort to fill the scallop by welding or the like in order to reinforce it.

  The present invention has been made to review the shape of the scallop in view of the above circumstances, and can reduce the concentration of strain on the scallop bottom without providing another configuration for reinforcement. An object of the present invention is to provide a scallop and a beam-end joint at a beam end capable of suppressing the occurrence of cracks in the beam and preventing the lower flange of the H-shaped beam from breaking.

In order to solve the above problems, the present invention employs the following solutions.
That is, the scallops according to the present invention are provided at the end of the web of the H-shaped section beam in order to form a beam end site joint of the H-shaped section beam, and are provided on the lower flange side of the H-shaped section beam. A first open end, and a second open end located on a side opposite to the first open end, from the first open end, away from the end of the web. A first opening edge extending from the second opening end, a second opening edge extending away from an end of the web, the first opening edge and the second opening edge. And a third opening edge connecting the web, the first opening edge is a toe on the web side in a fillet provided at a portion where the web and the flange intersect. It is formed in an arc shape so as to intersect, and at one end on the first opening end side, the tangent line is A first arc portion that is parallel to an inner surface of the dice, and the third opening edge is formed in an arc shape that connects the first opening edge and the second opening edge. And a radius of curvature of the first circular arc portion is larger than a radius of curvature of the second circular arc portion.
The scallops according to the present invention are intended to alleviate the concentration of strain at the bottom of the scallop on the lower flange side, but the same scallop can be used for the upper flange side.

  According to this configuration, the lower flange side with respect to the radius of curvature of the second arc portion at the third opening edge connecting the first opening edge and the second opening edge. By increasing the radius of curvature of the first arc portion at the first opening edge located at the edge of the scallop, shear deformation of the web can be easily caused around the scallops. Thereby, it is possible to reduce the concentration of strain on the scallop bottom, and it is possible to suppress the occurrence of cracks on the scallop bottom. Here, the scalloped bottom in the present invention means the vicinity of one end on the first opening end side in the first arc portion. Furthermore, since the first opening edge is formed in an arc shape so as to intersect with the toe portion of the fillet portion on the web side, the thickness in the width direction of the H-shaped cross section is relatively large. Ductile cracks can be intentionally generated at the toe portion of the small fillet portion on the web side. This ductile crack does not propagate to the flange, and extends stably in the axial direction along the web-side toe of the fillet portion having a smaller tensile stress compared to the flange. It is possible to prevent the lower flange from breaking and impairing the seismic performance of the steel frame building.

Further, the first arc portion and the second arc portion are connected at a portion where an arc formed by the first arc portion and an arc formed by the second arc portion are a common tangent. It may be a thing.
According to this configuration, since the first arc portion and the second arc portion are continuously connected, the concentration of strain on the scallop bottom can be further alleviated. The generation of cracks can be further suppressed.

Further, in the scalloped shape as described above, it has a straight portion disposed in parallel with the inner surface of the nearest lower flange including the first open end, the first arc of the first arc portion May be connected to the straight portion at one end on the opening end side.
According to this configuration, it is possible to secure a sufficient space for welding the lower flange and the column, to stably weld the flange to the column, and to prevent welding defects. Can be.

Furthermore, in the present invention, it is preferable that the radius of curvature of the first circular arc portion is 2.5 times or more the radius of curvature of the second circular arc portion.
This alleviates the concentration of strain on the lower flange side of the scallop and stably suppresses the occurrence of cracks from the scallop.

  Further, the size of the scallops as described above is desirably as small as possible in order to stably secure the proof strength of the beam end site joint, but from the viewpoint of workability of welding the flange and the column, The dimension of the scallops in the direction from the lower flange side to the upper flange side is preferably 15 mm or more.

  Further, the formation of scallops as described above is usually performed by cutting, but in order to smooth the cut surface of the arc portion and suppress the occurrence of cracks, it is preferable to increase the radius of curvature of the cut as much as possible. . At this time, it is preferable that the scallops are formed by cutting with a cutter, and the radius of curvature of the second arc portion is 6 mm or more.

  According to the present invention, it is possible to alleviate the concentration of strain on the scallop bottom without providing another configuration for reinforcement, to suppress the occurrence of cracks on the scallop bottom, Can be prevented from breaking.

It is a perspective view showing the outline of the beam end spot joining part of an embodiment. FIG. 2 is a detailed view of a portion A in FIG. 1. FIG. 2 is a sectional view taken along a cutting line II in FIG. 1. It is a side view which shows the detail of the scallops which are the 1st aspect of embodiment. It is a side view which shows the detail of the scallops which are the 2nd aspect of embodiment. It is a side view which shows the detail of the scallops which are the 3rd aspect of embodiment. It is a side view which shows the detail of the scallops which are the 4th aspect of embodiment. It is a model figure showing the whole analysis model used by an example. It is explanatory drawing for demonstrating a bending angle. Analysis model NO. 12 is a distribution diagram showing an equivalent plastic strain distribution in No. 12. FIG. Analysis model NO. It is a distribution diagram which shows the equivalent plastic strain distribution in 45. Analysis model NO. 12 is a distribution diagram showing a plastic shear strain distribution in No. 12. FIG. Analysis model NO. 24 is a distribution diagram showing a plastic shear strain distribution at 24. FIG. 9 is a graph showing the relationship between the ratio of the radius of curvature of the first arc to the radius of curvature of the second arc based on the analysis result and the maximum equivalent plastic strain.

An embodiment according to the present invention will be described below with reference to FIGS. FIG. 1 and FIG. 2 show a beam end on-site joint 100 of the present embodiment. The beam end on-site joint 100 includes a column 110 and a beam 1 connected to the column 110. The column 110 is configured by connecting a plurality of column members 111 made of a steel material and formed in a square tubular shape in the axial direction.
Further, a pair of diaphragms 112, 112 for connecting to the beam 1 are provided at the column-beam joint 110a where the column 110 and the beam 1 are connected. Each of the diaphragms 112 is a so-called through-diaphragm formed in a substantially rectangular plate shape, and is disposed on both upper and lower ends of the column-beam joint 110a. Each is sandwiched. Each of the diaphragms 112 is integrated with the column-beam joint 110a and the column member 111 by welding or the like in a state where the peripheral portion protrudes from the side surface 111a of each column member 111.
Note that the beam end site joint is not limited to the through-diaphragm type structure as in the present embodiment. For example, a configuration in which the beam 1 is directly connected to the column 110 without the intermediary of the diaphragm may be used. The beam 1 may be connected to the beam 1 via a column 110 or a diaphragm.

The beam 1 is usually formed by an H-shaped section beam. In this embodiment, the beam 1 is formed by a welded H-shaped cross section. The beam 1 extends in one direction (horizontal direction) as a whole, and includes a web 10 and both end portions in a direction orthogonal to the axial direction of the web 10 (hereinafter, end portions in a direction orthogonal to the axial direction of the web (10)). May be referred to as an "edge.") 10b, and a pair of flanges 20 connected to 10b.
The web 10 extends in the axial direction of the beam 1 with the direction orthogonal to the axial direction of the web 10, that is, the web width direction as the height direction of the beam 1. The pair of flanges 20 extend in the axial direction of the beam 1 and are connected to both edges 10b, 10b of the web 10. The pair of flanges 20 project from the web 10 at right and left ends of the web 10 at substantially right angles in the thickness direction of the web 10. The end of the beam 1 in the axial direction is connected to the peripheral surface of the column 110. The lower flange 20 of the pair of flanges 20 is referred to as a lower flange, and the upper flange 20 is referred to as an upper flange.
Here, in the present invention, the axial end of the beam connected to the column is referred to as an axial end (1a), and the portion of the beam at which the web and the flange are connected to the column is the axial end. (10a, 20a).

As shown in FIG. 3, the H-shaped cross section of the contact assembly in this embodiment has a fillet portion 30 formed by welding at a portion where the web 10 and the pair of flanges 20 intersect. That is, the fillet portion 30 is formed by melting the welding material or the welding material and the base material. Fillet portions 30 are formed between both web surfaces 11, 11 of web 10 and inner surfaces 21, 21 which are inner surfaces of the pair of flanges 20 facing each other, at both edges 10 b, 10 b of web 10. Have been. In other words, the fillet portion 30 is provided on each of the web surfaces 11, 11 such that the web 10 is sandwiched between the edges 10b, 10b of the web 10.
In addition, as shown in FIG. 3, in the present embodiment, the fillet portion 30 extends from the web toe portion 31 connected to the web surface 11 of the web 10 to the inner surface 21 of the flange 20 in the cross section of the beam 1 as viewed in the axial direction. It is formed in a triangular shape having a linear inclined surface that connects to the flange toe portion 32 that is connected to the toe, and in the present embodiment, is formed in an isosceles triangular shape in cross section. The size of each side of the fillet portion 30 along the web surface 11 of the web 10 and the inner surface 21 of the flange 20, that is, the fillet height Hf that is the distance from the inner surface 21 of the flange 20 to the web toe end 31, and The fillet width Wf, which is the distance from the web surface 11 of the web 10 to the flange toe 32, is, for example, about 3 to 30 mm.

The cross section of the fillet portion 30 is not limited to a triangular shape. The web toe end 31 and the flange toe end 32 may be connected by an arcuate concave curved surface, and the tangents of the concave surface at the web toe end 31 and the flange toe end 32 are equal to the web surface 11 of the web 10 and the flange 20. May be connected so as to be parallel to the inner surface 21. Further, the web toe end 31 and the flange toe end 32 may be connected by a convex curved surface.
In the present embodiment, as described above, the fillet portion 30 is formed by performing fillet welding between the web 10 and the flange 20, and the fillet portion 30 and the web 10 and the flange near the fillet portion 30 are formed. A welded portion is formed by each of the portions 20 and 20.

The beam 1 is connected to the column 110 by the end connection structure 200 of the H-shaped section member of the present embodiment. That is, the end connection structure 200 of the H-shaped section member of the present embodiment includes a flange welded portion 40 for welding the shaft end 20a of the flange 20 of the beam 1 to the column 110, and a shaft end 10a of the web 10 of the beam 1 110 and a web welding portion 50 to be welded. In addition, a backing metal is provided on the lower surface side of the flange welded portion 40 to prevent the molten metal forming the flange welded portion 40 from dropping out of the flange 20 from between the groove surface 40a and the column 110. .
In the present embodiment, the shaft end 20a of the flange 20 is welded to the diaphragm 112 of the column 110, and the shaft end 10a of the web 10 is welded to the side surface 111a of the column member 111.

A scallops 60 are provided on the shaft end 10 a of the web 10 in the beam 1. The scallops 60 are located at the positions of the two edges 10b and 10b on the shaft end 10a side of the web 10 on the pair of flanges 20 and 20 side, in the direction of the shaft end 20a side of the nearest flange 20 and the shaft end 10a side of the web 10. The web 10 is provided so as to open in the thickness direction of the web 10. Thus, the flange weld portion 40 is formed from one end in the width direction of the flange 20 to the other end in the width direction across the web 10 through the scallops 60. The web welding portion 50 is formed up to scallops 60 provided on both edges 10b, 10b of the web 10.
In the present embodiment, the web 10 of the beam 1 is connected to the column 110 by welding the shaft end 10a to the column 110, but the method of joining the shaft end of the beam web is limited to welding. Instead, for example, bolt joining may be used.

  As shown in FIG. 4, the scallops 60 have openings that open in the direction of the shaft end 20a side of the nearest flange 20 and the shaft end 10a side of the closest web 10 as described above. Includes open ends. That is, the first opening end 60a located on the nearest flange 20 side and the side opposite to the first opening end 60a, in other words, the center side of the web 10 sandwiched between the pair of flanges 20 in the web width direction. And a second open end 60b located there. More specifically, the first open end 60a is formed at a position on the inner surface 21 side of the nearest flange 20 and the second open end 60b is formed at the shaft end 10a of the web 10.

  The scallops 60 have a first opening edge 61, a second opening edge 62, and a third opening edge 63. The first opening edge 61 includes a first opening end 60a, and extends from the first opening end 60a in a direction away from the axial end 1a in the axial direction of the beam 1. The second opening edge 62 includes a second opening end 60b, and extends from the second opening end 60b in a direction away from the axial end 1a of the beam 1, that is, toward the center of the beam 1 in the axial direction. . The third opening edge 63 connects the first opening edge 61 and the second opening edge 62.

Specifically, the first opening edge portion 61 is formed in an arc shape so as to intersect with the web toe end portion 31 in the fillet portion 30, and the tangential line is formed at one end 71a on the first opening end 60a side. It has a first arc portion 71 which is parallel to the inner surface 21 of the flange 20.
The shape of the second opening edge portion 62 is not particularly limited, but in the case of the present embodiment, extends linearly from the second opening end 60b.
The third opening edge 63 has a second arc portion 72 formed in an arc shape that curves from the first opening edge 61 to the second opening edge 62.
Here, it is desirable that the radius of curvature R1 of the first circular arc portion 71 be 2.5 times or more the radius of curvature R2 of the second circular arc portion 72. The reason why the radius of curvature R1 of the first circular arc portion 71 is set to be 2.5 times or more the radius of curvature R2 of the second circular arc portion 72 is that concentration of strain on the flange 20 side of the scallop 60 is reduced. This is because it is possible to more stably suppress the occurrence of cracks from the scallops 60.

In the scallop 60 constituted by the first opening edge 61, the second opening edge 62, and the third opening edge 63, the direction in which the pair of flanges 20 are separated from each other (the height direction of the beam 1). It is desirable that the height dimension Hs of the scallop 60 be as small as possible in order to stably secure the proof stress of the beam end site joint portion 100. However, from the viewpoint of the workability of welding the flange 20 and the column 110, It is desirable that the dimension in the direction from the lower flange 20 side toward the upper flange 20 side be 60 mm or more. Further, the height dimension Hs of the scallop 60 may be 35 mm or less in order to transmit the moment more efficiently even in the web 10 and further reduce the concentration of strain on the flange 20 side of the scallop 60.
The radius of curvature R2 of the second circular arc portion 72 may be 6 mm or more in order to ensure workability in consideration of cutting with a cutter when forming scallops.

Hereinafter, a more detailed embodiment of the scallops 60 will be described.
FIG. 4 shows the scallops 60 of the first embodiment. As shown in FIG. 4, in the scallops 60 according to the first embodiment, the first opening edge portion 61 is disposed at a position on the nearest flange 20 side and includes a first opening edge 60 a including a first opening end 60 a. It has a straight portion 73 and a first circular arc portion 71 connected to the first straight portion 73.
The first straight portion 73 corresponds to the portion of the web 10 cut away by the scallops 60 on the inner surface 21 of the nearest flange 20, and in this embodiment, is included in the inner surface 21 of the closest flange 20. I have. The first open end 60 a is provided at the shaft end 20 a of the nearest flange 20, and more specifically, a groove surface used when forming the flange welded portion 40 to be welded to the column 110. The end on the web 10 side at 40a is the first open end 60a.
The first arc portion 71 is arranged such that a tangent at a position where the first arc portion 71 is connected to the first linear portion 73 is parallel to the inner surface 21 of the flange 20, and gradually moves away from the flange 20 as the distance from the shaft end 1 a of the beam 1 increases. It is formed in a curved concave curve shape. The first arc portion 71 is connected to the first straight portion 73 and crosses the fillet portion 30, and one end portion of the fillet cross portion 71 c opposite to the nearest flange 20. And a web forming portion 71d formed along the web surface 11 of the web 10 from the web.

On the other hand, the second opening edge portion 62 is formed in a linear shape including the second opening end 60b, and has a second linear portion 74 extending along the axial direction of the beam 1.
Further, the third opening edge 63 has a second arc portion 72, and one end 72 a of the second arc portion 72 is connected to the first arc portion 71 of the first opening edge 61. The other end 72b is connected to the second linear portion 74 of the second opening edge 62.
Here, the first arc portion 71 and the second arc portion 72 are connected at a portion where an arc formed by the first arc portion 71 and an arc formed by the second arc portion 72 form a common tangent. I have. In the connection portion between the second arc portion 72 and the second straight portion 74, the tangent of the arc forming the second arc portion 72 and the second straight portion 74 coincide. Thereby, the shape of the edge of the scallops 60 constituted by the first opening edge 61, the second opening edge 62, and the third opening edge 63 is continuous.
In this embodiment, the height Hs of the scallops 60 is determined by the distance between the first straight portion 73 and the second straight portion 74.

FIG. 5 shows a scallops 60A according to the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 5, in the scallops 60 </ b> A of the second embodiment, the first opening edge 61 does not include a portion corresponding to the first linear portion 73 in the first embodiment, and One end 71a on the nearest flange 20 side is the first open end 60a. One end 71a of the first circular arc portion 71 serving as the first open end 60a is located on the inner surface 21 of the flange 20, and a tangent at the one end 71a is parallel to the inner surface 21 of the flange 20.
In the present embodiment, the height Hs of the scallops 60 is determined by the distance between one end 71a of the first circular arc portion 71 and the second linear portion 74.

FIG. 6 shows a scallop 60B according to a third embodiment. Similarly, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 6, in this embodiment, the groove surface 40 a used when forming the flange welded portion 40 is directed upward (strictly, in a direction away from the axial end portion 1 a of the beam 1 gradually as going upward) ), And one end of the groove surface 40 a is located closer to the center in the web width direction than the inner surface of the nearest flange 20. One end of the groove surface 40a is a first opening end 60a.
Specifically, the scallops 60 </ b> B have a first opening edge 61, a first straight portion 75 including the first opening end 60 a, and a first arc portion 71 connected to the first straight portion 75. And the first linear portion 75 is separated from the inner surface 21 of the flange 20 by the amount that the first opening end 60a is located closer to the center in the web width direction than the inner surface of the nearest flange 20. And is formed parallel to the inner surface 21 of the flange 20.
Here, the scallop separation distance Xs represented by the distance between the first straight portion 75 and the inner surface 21 of the flange 20 is a corner that is at least the distance from the web toe end 31 of the fillet portion 30 to the inner surface 21 of the flange 20. It is smaller than the meat height Hf. Thereby, the first arc portion 71 connected to the first straight portion 75 intersects with the web toe portion 31.
In this embodiment, the height Hs of the scallops 60 is determined by the distance between the first straight portion 75 and the second straight portion 74.

FIG. 7 shows a scallops 60C according to a fourth embodiment. Note that the same components as those of the third embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 7, in the scallops 60 </ b> C of the fourth embodiment, the first opening edge portion 61 does not include a portion corresponding to the first linear portion 75 in the third embodiment, and One end 71a is the first open end 60a. One end 71a of the first arcuate portion 71 serving as the first open end 60a is separated from the inner surface 21 of the flange 20 as in the third embodiment, and the tangent at the one end 71a is parallel to the inner surface 21 of the flange 20. It has become.
Here, the scallop separation distance Xs represented by the distance between one end 71 a of the first circular arc portion 71 and the inner surface 21 of the flange 20 is at least the distance from the web toe end 31 of the fillet portion 30 to the inner surface 21 of the flange 20. Is smaller than the fillet height Hf. Thereby, the first arc portion 71 connected to the first straight portion 73 intersects the web toe portion 31.
In the present embodiment, the height Hs of the scallops 60 is determined by the distance between one end 71a of the first circular arc portion 71 and the second linear portion 74.

In the first to fourth aspects, the first arc 71 of the first opening edge 61 and the second arc 72 of the third opening edge 63 are the first arc 71 And the arc formed by the second arc portion 72 are connected at a portion where a common tangent line is formed. However, the first circular arc portion 71 and the second circular arc portion 72 may not be connected at a common tangential portion, that is, may be connected in a state where a corner serving as a boundary is formed. Further, a linear portion is provided between the first circular arc portion 71 and the second circular arc portion 72, and the first circular arc portion 71 and the second circular arc portion 72 are indirectly connected. There may be.
Further, the second opening edge portion 62 is a straight portion in the present embodiment, but may have any shape, for example, may be formed in an arc shape.

In the end connection structure 200 of the H-shaped section member as described above, the second arc portion 72 at the third opening edge 63 that connects the first opening edge 61 and the second opening edge 62 is formed. At the same time, the first arc portion 71 at the first opening edge portion 61 located on the flange 20 side is provided, and the first arc portion 71 has a radius of curvature that is 2.5 times or more larger than the second arc portion 72. May be.
Thereby, the concentration of strain on the flange 20 side of the scallops 60 can be reduced, and the occurrence of cracks from the scallops 60 can be suppressed. And since such a 1st circular arc part 71 is formed so that it may intersect with the web toe end part 31 in the fillet part 30, even if a ductile crack generate | occur | produces, a width | variety will be relatively. A narrow cross section can be formed in the vicinity of the web toe 31 where the cross section changes from the web 10 to generate a crack. Even if a ductile crack is generated near the toe on the web 10 side, the generated crack is stable in the axial direction along the web toe 31 having a lower tensile stress than the flange 20. Cracks can propagate. Therefore, in the end connection structure 200 of the H-shaped section member as in the present embodiment, even if an additional configuration is not provided to reinforce, the occurrence of the initial crack from the scallop is delayed while the initial Even if a crack occurs, the ductile crack can be propagated so as not to cause early fracture, and the beam end in-situ joint 100 with higher safety can be obtained.

Further, by setting the height of the scallops 60 to 15 mm or more, the workability of welding the flange 20 and the column 110 can be improved.
Further, by setting the height of the scallops 60 to 35 mm or less, the moment can be transmitted more efficiently by the web 10, so that the yield bending strength as a joint between the column 110 and the beam 1 can be improved. it can. In addition, by keeping the height of the scallops 60 low, the moment can be transmitted more efficiently by the web 10, so that the concentration of strain on the flange 20 side of the scallops 60 can be further reduced.
Furthermore, since the first arc portion 71 and the second arc portion 72 are connected by a common tangent, the first arc portion 71 and the second arc portion 72 are smoothly connected without unevenness. Therefore, the concentration of strain can be further alleviated, and the occurrence of cracks can be more stably suppressed.
Further, by setting the radius of curvature R2 of the second arc portion 72 to 6 mm or more, the concentration of strain in the second arc portion 72 can be reduced, and the scallop can be easily cut by a cutter to form. Can be.

  Further, the end connection structure 200 of the H-shaped section member has the first opening edge 61 having the first opening end 60a and the inner surface 21 of the flange 20 as in the third aspect described above. It may have a straight portion 75 arranged in parallel, and one end 71a of the first arc portion 71 may be connected to the straight portion 75, thereby welding the shaft end 20a of the flange 20. A sufficient space can be secured, and the welding between the flange 20 and the column 110 can be performed stably, so that welding defects can be prevented.

In order to demonstrate the effect of the present invention, numerical analysis was performed on a specific example of the beam end in-situ joint 100 as in the above embodiment.
The finite element method was used as the analysis method, and ANSYS. Ver16 was used. FIG. 8 shows the entire model of the beam end site joint 100 as an analysis model for performing the analysis in the present embodiment. As shown in FIG. 8, the analysis model was a cantilever beam type, and a half model was used in the width direction of the beam 1 in consideration of symmetry. The analysis model was created with a three-dimensional solid element using 8-node hexahedral elements. The material properties of the steel material used for the column 110 and the beam 1 were the same material for both the column 110 and the beam 1, and the stress-strain curve obtained from the material test result of SN490B was modeled by a plurality of linear components. Was used.
As the cross section of the H-shaped cross section beam used as the beam 1, the cross section Db shown in FIG. 3 was 700 mm, the width B was 200 mm, the thickness tbw of the web 10 was 16 mm, and the thickness tbf of the flange 20 was 22 mm. Here, the shape of the fillet portion 30 is the fillet height Hf from the inner surface 21 of the flange 20 to the web toe portion 31 and the fillet width Wf from the web surface 11 of the web 10 to the flange toe portion 32. They are equal isosceles triangles, and Hf = Wf = 18 mm. The length Lb from the side surface of the pillar 110 to the end of the beam 1 in the axial direction was 3500 mm. The thickness td (see FIG. 2) of the diaphragm 112 on the column 110 side to which the shaft end 20a of the flange 20 is welded was 32 mm. Although not shown, the outer diameter Bc of the column 110 was 500 mm, and the plate thickness tcf was 16 mm.

  The analysis was performed on 53 types of models while changing parameters relating to the shape of the scallops 60. The shapes of the scallops 60 used as the analysis model include those shown in FIGS. In addition, the second opening edge portion 62 is constituted only by the second linear portion 74, and the first arc portion 71 and the second arc portion 72 are continuously connected by a common tangent line. The parameters related to the shape of the scallops 60 include the radius of curvature R1 (mm) of the first arc portion 71, the radius of curvature R2 (mm) of the second arc portion 72, and the length of the first linear portion 73 (75). There are a length L1, a scallop separation distance Xs (mm), and a height Hs of the scallop 60. The arcuate end height Hc, which is the height of the other end 71b of the first arcuate part 71 on the side away from the shaft end 1a from the inner surface 21 of the flange 20, is equal to the radius of curvature R1 of the first arcuate part 71 ( mm), the radius of curvature R2 (mm) of the second arc portion 72, the scallop separation distance Xs, and the height Hs of the scallop 60 are geometrically determined. Tables 1 and 2 show parameter values of each analysis model.

As shown in Tables 1 and 2, NO. In 1 to 25, while changing the above parameters, the radius of curvature R1 of the first arc portion 71 is set to be larger than 1.0 times the radius of curvature R2 of the second arc portion 72, and the first arc portion 71 The intersection with the web toe 31, that is, the arc-shaped terminal end height Hc was equal to or greater than the fillet height Hf.
On the other hand, NO. In steps 26 to 39, while changing the above parameters, the radius of curvature R1 of the first circular arc portion 71 is set to be larger than 1.0 times the radius of curvature R2 of the second circular arc portion 72, and the height Hc of the circular arc terminal is set. The fillet height was less than Hf.
In addition, NO. In 40 to 44, while changing the above parameters, the radius of curvature R1 of the first circular arc portion 71 is set to be less than 1.0 times the radius of curvature R2 of the second circular arc portion 72, and the circular arc terminal end height Hc is reduced. The fillet height was set to Hf or more.
Further, NO. In 45 to 53, while changing the above parameters, the radius of curvature R1 of the first circular arc portion 71 is set to less than 1.0 times the radius of curvature R2 of the second circular arc portion 72, and the circular arc terminal end height Hc is reduced. The fillet height was less than Hf.

  With respect to these analytical models, a load was applied to the axial end of the beam 1 to deform the beam 1. Then, as shown in FIG. 9, the rotation angle θ at the loading point of the beam 1 (the angle formed by a line L2 connecting both ends of the axis L1 of the beam 1 after deformation with respect to the axis L0 of the beam 1 before deformation) is The rotation angle when the entire cross section is plasticized at the shaft end 1a is θp, and the beam 1 is deformed to an angle 3 · θp that is three times this. Then, the equivalent plastic strain distribution and the plastic shear strain distribution at θ = 3 · θp were determined by the finite element method. As an example, FIG. 12 shows the equivalent plastic strain distribution of FIG. 45 shows an equivalent plastic strain distribution of 45. As an example, FIG. 13 shows the plastic shear strain distribution of FIG. 24 shows a plastic shear strain distribution of No. 24. Further, the maximum equivalent plastic strain εmax (%) at the scallop bottom of the scallop 60 was determined based on the analysis result by the finite element method. Tables 1 and 2 show the maximum equivalent plastic strain εmax in each analysis model. FIG. 14 is a graph plotting the relationship between the ratio R1 / R2 of the radius of curvature R1 of the first circular arc portion 71 to the radius of curvature R2 of the second circular arc portion 72 and the corresponding maximum equivalent plastic strain εmax. Note that a dotted line P1 parallel to the horizontal axis indicates εmax = 20%. A dotted line Q1 parallel to the vertical axis indicates a ratio R1 / R2 = 1.0.

  From Tables 1 and 2 and FIG. 14, the maximum equivalent plastic strain εmax tends to decrease by increasing the ratio R1 / R2 of the radius of the first arc portion 71 to the radius of the second arc portion 72. I understand. In particular, in the analysis case where R1 / R2 exceeds 1.0, εmax remains at a low value of about 20% or less regardless of the value of each analysis parameter. That is, when R1 / R2 exceeds 1.0, the concentration of strain on the scallop bottom is reduced as compared to when R1 / R2 is 1.0 or less. In order to more stably reduce the concentration of strain on the scallop bottom, it is desirable to make R1 / R2 larger. In consideration of the variation in toughness of the H-shaped section beam, R1 / R2 becomes 2.5. It is desirable to make the above. As shown in FIG. 10, in the analysis model in which R1 / R2> 1.0, for example, the analysis model No. shown in FIG. As shown in FIG. 12, the maximum equivalent plastic strain εmax at the scalloped bottom can be suppressed, and in particular, the equivalent plastic strain near the one end 71a where the tangent line is parallel to the inner surface 21 of the flange 20 in the first arc portion 71 can be suppressed. Is admitted. That is, by setting R1 / R2> 1.0, it is possible to suppress the occurrence of a crack in the vicinity of the intersection between the web 10 and the flange 20. For this reason, by adopting a structure like an analysis model in which R1 / R2> 1.0, it is possible to suppress the occurrence of a crack in the first circular arc portion 71 at the time of a maximum earthquake, Propagation toward the outer surface 22 (see FIG. 3) can be suppressed. On the other hand, in the analysis model with the ratio R1 / R2 ≦ 1.0, the analysis model NO. As in the case of 45, the maximum equivalent plastic strain εmax at the scalloped bottom is increased, and the equivalent plastic strain in the vicinity of one end 71a where the tangent is parallel to the inner surface 21 of the flange 20 can be suppressed, particularly in the first arc portion 71. Not admitted. As described above, the generation of a crack in the vicinity of the intersection between the web 10 and the flange 20 cannot be suppressed. For this reason, in a structure like an analytical model in which R1 / R2 ≦ 1.0, a crack is generated in the first arc portion 71 at the time of the maximum earthquake, and the crack is directed toward the outer surface 22 of the flange 20. There is a risk of progress. When the crack propagates toward the outer surface 22 of the flange 20, a high tensile stress is acting on the flange 20, which promotes brittle fracture of the flange.

  In the analysis model satisfying Hc ≧ Hf, the analysis model No. shown in FIG. As shown in FIG. 12, the distribution of the plastic shear strain along the vicinity of the web toe portion 31 in the fillet portion 30 is formed broader in the direction of the material axis of the beam 1, and the numerical value of the strain is higher. . That is, in the shape of the scallop 60 in which the first arc portion 71 intersects the web toe 31 due to Hc ≧ Hf, a ductile crack occurs near the web toe 31 and the generated crack has a cross section. The H-shaped portion can be stably developed in the axial direction along the web toe portion 31 of the fillet portion 30 having a relatively small thickness in the width direction. That is, it is possible to suppress the fracture caused by the crack heading to the outer surface 22 of the flange 20, further clarify the place where the crack occurs, make it easy to visually recognize the crack after the maximum earthquake, and perform the repair quickly and It can also be easily performed. On the other hand, the analysis model NO. In FIG. 24, as shown in FIG. 13, the first arc portion 71 does not intersect with the web toe portion 31 of the fillet portion 30, and the second arc portion 72 is also included in the fillet portion 30, so No plastic shear strain distribution is formed along the axial direction of the beam. Therefore, a crack is generated in the first arc portion 71. Since the crack propagates inside the fillet portion 30, it is difficult to detect the occurrence of the crack, and the crack propagates toward the outer surface 22 of the flange 20 to promote brittle fracture of the flange.

The embodiments and examples of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiments and the examples, and a design change within a range not departing from the gist of the present invention. Etc. are also included.
For example, in the above embodiment, the H-section steel connected to the column has a welded H-section, but is not limited thereto, and may be a rolled H-section steel. In the case of the rolled H-section steel, the fillet portion 30 is also formed of the base material.

1 beam (H-shaped section beam)
1a Shaft end 10 Web 20 Flange 30 Fillet 60, 60A, 60B, 60C Scallop 60a First opening end 60b Second opening end 61 First opening edge 62 Second opening edge 63 Third Opening edge portion 71 First arc portion 72 Second arc portion 73 First linear portion (linear portion)
R1 Radius of curvature of first circular arc portion R2 Radius of curvature of second circular arc portion Hs Height of scallop 100 Beam end site joint 110 Column 200 H end connection structure of H-shaped section member

Claims (7)

A scallops provided at an end of a web of the H-shaped beam to form a beam end field joint of the H-shaped beam,
A first open end located on the lower flange side of the H-shaped section beam;
A second opening end located on a side opposite to the first opening end,
A first opening edge extending away from the end of the web from the first opening end; and a second opening edge extending away from the end of the web from the second opening end. When,
Having a third opening edge connecting the first opening edge and the second opening edge,
The first opening edge portion is formed in an arc shape so as to intersect with a toe portion on the web side in a fillet portion provided at a portion where the web and the lower flange intersect, At the one end on the open end side, a first arc portion whose tangent line is parallel to the inner surface of the lower flange,
The third opening edge has a second arc portion formed in an arc shape connecting the first opening edge and the second opening edge, and the first arc portion is A scallops having a radius of curvature larger than a radius of curvature of the second arc portion.   The first arc portion and the second arc portion are connected at a portion where an arc formed by the first arc portion and an arc formed by the second arc portion form a common tangent. 2. The scallops according to 1.   The first opening edge has a straight portion disposed parallel to an inner surface of the nearest lower flange including the first opening end, and the first opening of the first arc portion. The scallops according to claim 1 or 2, wherein one end on the end side is connected to the straight portion.   The scallops according to any one of claims 1 to 3, wherein a radius of curvature of the first arc portion is 2.5 times or more a radius of curvature of the second arc portion.   The scallop according to any one of claims 1 to 4, wherein a dimension of the scallop in a direction from the lower flange side to the upper flange side is 15 mm or more.   The scallops according to any one of claims 1 to 5, wherein the scallops are formed by cutting with a cutter, and a radius of curvature of the second arc portion is 6 mm or more.   A beam end in-situ joint formed using the scallops according to any one of claims 1 to 6.