KR102307939B1 - Connecting sturcture between column and beam - Google Patents

Abstract

The present invention is a pillar; a beam having an end joined to the column, a pair of flange members facing each other, and a web member connecting between the pair of flange members; and a stiffener installed at a joint portion between the column and the beam, wherein the stiffener includes: a first stiffener joined to the column and the flange member, the first stiffener having a relatively large width; a second stiffener joined to the flange member and having a relatively smaller width than the first stiffener of the beam; and a third stiffener formed between the first stiffener and the second stiffener and having a curved line whose cross section decreases from the first stiffener toward the second stiffener. It provides a joint structure of a column and a beam, characterized in that the plastic hinge is generated in the longitudinal region.

Description

Column and beam joint structure {CONNECTING STURCTURE BETWEEN COLUMN AND BEAM}

The present invention relates to a joint structure of a column and a beam with reinforced strength.

It should be noted that the content described in this section merely provides background information on the present invention and does not constitute the prior art.

In recent years, as the number and intensity of earthquakes are increasing worldwide, interest in seismic design is increasing.

In general, a steel structure is lighter than a reinforced concrete structure, and it is known that it has excellent deformability and thus excellent seismic performance.

However, despite the strengths of steel structures, there are many cases in which brittle fractures at the beam-column junction, where the force is concentrated, occur in the event of a large earthquake, resulting in the collapse of the building or major damage.

It is important not only to the material of the steel structure, but also to have an organic relationship such as the strength ratio of beams and columns, beam-column connection details, welding quality, and construction.

In terms of materials, the quality of steel structure materials has improved recently, and materials with a yield ratio of 0.85 or less as well as 0.8 or less have been developed, which is advantageous for seismic performance.

In addition, the beam-column connection details include the RBS method in which a part of the beam cross-section is removed to improve ductility and prevent brittle fracture on the side of the joint.

And in Korea, there are attempts to prevent brittle fracture and reinforce strength by attaching end reinforcing plates.

In order to improve the seismic performance of steel structures, seismic design, seismic material selection, joint detail, welding and other manufacturing quality, and minimization of construction errors must be combined.

KR 20-0279918 Y1

An aspect of the present invention is to provide a joint structure of a column and a beam that can reinforce the strength of the joint between the column and the beam and prevent brittle fracture.

수학식 (2):

여기서, LS : 스티프너의 길이, h: 보의 춤(높이), ba: 제2 스티프너의 폭, tf: 보의 플랜지부재의 두께이다.
수학식 (3):

수학식 (4):

여기서, bn: 제1 스티프너의 폭, bf: 보의 플랜지부재의 폭, da: 제1 스티프너의 길이이다. As an aspect for achieving the above object, the present invention is a pillar; A beam having an end joined to the column, a pair of flange members facing each other, and a web member connecting between the pair of flange members; and a stiffener installed at a joint portion between the column and the beam, wherein the stiffener includes: a first stiffener joined to the column and the flange member, the first stiffener having a relatively large width; a second stiffener joined to the flange member and having a relatively smaller width than the first stiffener of the beam; and a third stiffener formed between the first stiffener and the second stiffener and having a curved line whose cross section decreases from the first stiffener toward the second stiffener. A plastic hinge is generated in the longitudinal region, and the following formulas (1), (2), (3), and (4) are provided.
Equation (1):

Equation (2):

Here, LS: the length of the stiffener, h: the dance (height) of the beam, ba: the width of the second stiffener, tf: the thickness of the flange member of the beam.
Equation (3):

Equation (4):

Here, bn: the width of the first stiffener, bf: the width of the flange member of the beam, da: the length of the first stiffener.

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Preferably, the following Equations (5) to (7) may be satisfied so that the plastic hinge is generated in the longitudinal region of the second stiffener.

Equation (5):

,

Equation (6):

,

,Equation (7):

,

Here, M pA : total plastic moment of section A, M pB : total plastic moment of section B, M pC : , total plastic moment of section C, L: length of beam, L _S : length of stiffener, L _S1 : length of first stiffener The sum of the length and the length of the third stiffener, L _S2 : Length of the second stiffener, b _a : Width of the second stiffener, b _n : Width of the first stiffener, t _f is the thickness of the flange member of the beam, b _f : Width of the flange member of the beam, b _af : the sum of the width of the flange member of the beam and the width of the pair of second stiffeners, b _nf : the sum of the width of the flange member of the beam and the width of the pair of first stiffeners, d _a : the length of the first stiffener, d _b : the sum of the lengths of the second stiffener and the third stiffener, t _f : the thickness of the flange member of the beam, h: the dance (height) of the beam.

Preferably, the beam may be welded in a state in which the entire section in the width direction of the pair of flange members and the entire section in the height direction of the web member are in contact with the column.

Preferably, the stiffener may be formed at both ends of the flange member in the width direction, respectively.

Preferably, in the third stiffener, an arc-shaped curved line whose cross section decreases from the first stiffener to the second stiffener is formed, and the curved line may be formed throughout the longitudinal direction of the third stiffener. .

According to an embodiment of the present invention, there is an effect of reinforcing the strength of the joint portion of the column and the beam, and preventing brittle fracture.

1 is a view showing the reinforcement of the beam and column joints by a method other than the present invention.
2 is a perspective view of a joint structure of a beam and a column according to an embodiment of the present invention.
3 is a plan view of a beam and a stiffener showing dimensions for designing a stiffener in a joint structure of a beam and a column according to an embodiment of the present invention.
4 is a view showing the holding strength and the generation moment in the joint structure of the beam and the column according to an embodiment of the present invention.
Figure 5a is a view showing a test object according to an embodiment of the joint structure of the beam and the column according to an embodiment of the present invention.
FIG. 5B is a view showing before and after an experiment using the test object of FIG. 5A.
FIG. 6 is a diagram illustrating a relationship between a moment and a rotation angle according to an experiment performed by the test object of FIG. 5A.
FIG. 7 is a diagram illustrating a relationship between a moment and a plastic rotation angle according to an experiment performed by the test object of FIG. 5A.
FIG. 8 is a view showing tensile strain for each section according to an experiment performed by the test specimen of FIG. 5A.
FIG. 9 is a view showing tensile strain for each 0.05 rad section of FIG. 8 .
10A and 10B are diagrams illustrating a finite element analysis process for verifying the analytical performance of a joint structure of a beam and a column according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. The shapes and sizes of elements in the drawings may be exaggerated for clearer description.

Referring to FIG. 1 , a joint portion between the column 100 and the beam 200 may be formed while the beam 2 is joined to the column 1 , and an end reinforcing plate is formed between the column 1 and the beam 2 . (3) can be joined.

As shown in Fig. 1, the general end reinforcing plate 3 reinforcement method is a method that can retain high strength compared to non-reinforced beams by reinforcing the end reinforcing plates 3 at the end where the maximum load occurs at the junction. am.

However, there is a problem that, if simply reinforced with the end reinforcing plate end reinforcing plate 3 may cause a brittle fracture portion 4 at the end of the welded portion.

The joint structure of the column 100 and the beam 200 of the present invention is intended to improve the seismic performance through design, manufacturing quality, etc. including material and joint detail, and according to the present invention, the beam 200 dance (height) 1,000 The performance of special moment joints, which are the highest-grade seismic joints up to mm, can be secured.

The joint structure of the present invention is not the main purpose of simply reinforcing the end of the joint portion of the column 100 and the beam 200 to increase the bearing strength, but rather the stress generated at the end of the joint portion by inducing the generation of plastic hinges. It aims to prevent brittle fracture by dissipating it over a wider area.

Hereinafter, a bonding structure according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 10B .

The bonding structure according to an embodiment of the present invention may include a column 100 , a beam 200 , and a stiffener 300 .

Referring to FIG. 2 , the bonding structure includes a pillar 100 , a pair of flange members 210 having an end joined to the pillar 100 , and a pair of flange members 210 installed to face each other, and the pair of flange members 210 . It may include a beam 200 having a web member 230 for connecting them, and a stiffener 300 installed at a joint portion of the column 100 and the beam 200 .

2 and 3, the stiffener 300 is joined to the column 100 and the flange member 210, and a first stiffener 310 having a relatively large width, and the flange member. A second stiffener 320 bonded to 210 and having a relatively smaller width than the first stiffener 310 of the beam 200, and the first stiffener 310 and the second stiffener 320 ) and having a third stiffener 330 formed between the first stiffener 310 and a curved line whose cross section decreases in the direction from the second stiffener 320 in the direction, the second stiffener 320 is provided. A plastic hinge may be generated in the longitudinal direction (D2) region of .

The pillar 100, the beam 200, and the stiffener 300 applied to the present invention may be made of a metal material such as steel, and the pillar 100, the beam 200, and the stiffener 300 may be welded to each other. have.

For example, the steel material applied to the joint structure uses SN steel, which has the best seismic performance in KS, so that the yield ratio of the material is controlled to 0.8 or less, and the basic seismic performance of the structure can be improved by improving the welding performance.

Referring to FIG. 2 , the pillar 100 may be formed of a steel section having an H-shaped cross-section or an I-shaped cross-section.

Referring to FIG. 2 , the pillar 100 may include a pair of pillar flanges 110 that are installed to face each other, and a pillar web 120 connecting the pair of pillar flanges 110 .

A pair of column flanges 110 and the column web 120 can be included to form an H-shaped or I-shaped cross-section in the transverse direction.

The pillar 100 may further include a horizontal reinforcing plate 130 installed between the pair of pillar flanges 110 and the pillar web 120 to reinforce the H-type or I-shaped cross section in the transverse direction.

The pillar 100 may be composed of a steel pipe having a rectangular cross section, and the beam 200 may be welded to each side of the rectangular cross section of the pillar 100 .

Of course, the column 100 may be composed of a steel pipe having a polygonal cross-section, and the beam 200 may be welded to each side of the polygonal cross-section of the column 100 .

Of course, the pillar 100 may include other additional components in addition to the pillar flange 110 and the pillar web 120, of course.

Referring to FIG. 2 , the beam 200 may be joined so that the end thereof crosses the column 100 .

The beam 200 may include a pair of flange members 210 and a web member 230 .

A pair of flange members 210 are formed to extend in the longitudinal direction (D2) and are connected by the web member 230 in a state in which they are spaced apart from each other in the height direction to form an H-shaped or I-shaped cross section in the longitudinal direction. can do.

A pair of flange member 210 and the web member 230 may be welded in a state in which the end in the longitudinal direction (D2) is in contact with the column flange 110 of the column 100 .

Of course, in addition to the flange member 210 and the web member 230, other additional components may be added to the beam 200, of course.

Referring to FIGS. 2 and 3 , the stiffener 300 may be installed at a joint portion between the pillar 100 and the beam 200 .

The stiffener 300 serves to induce a change in the generation position of the plastic hinge.

The stiffener 300 is bonded to the column 100 and the beam 200, respectively, to dissipate the stress generated at the end of the joint of the column 100 and the beam 200 to a wider area to prevent brittle fracture. .

That is, the stiffener 300 is installed at the joint portion of the column 100 and the beam 200, thereby dissipating the stress concentrated at the end of the beam 200 that is welded to the column 100 to a wider area, thereby dissipating the plastic hinge. It is possible to move the generation position of the hinge to a set position in the stiffener 300 in the end region of the beam 200, which is a joint portion of the column 100 and the beam 200.

Of course, the stiffener 300 may be respectively joined to the pillar 100 and the beam 200 to reinforce the connection portion between the pillar 100 and the beam 200 .

The stiffener 300 has an end welded to the column flange 110 of the column 100 and vertically welded to it, and may be welded in a horizontal direction so as to be disposed parallel to the flange member 210 of the beam 200 .

For example, the stiffener 300 may be manufactured separately from the beam 200 and welded to the beam 200 .

As another example, the stiffener 300 may be manufactured integrally with the beam 200 from the beginning. That is, the beam 200 and the stiffener 300 may be integrally manufactured without a separate joint portion.

The stiffener 300 may be formed at both ends in the width direction D1 of the flange member 210 of the beam 200 , and the ends may be joined to the column 100 .

2, the longitudinal direction (D2) end of the stiffener 300 is joined to the column flange 110 of the column 100, one side of the stiffener 300 in the longitudinal direction (D2) is the beam 200 It may be joined to the flange member 210 of the.

For example, the thickness of the stiffener 300 may be the same as the thickness of the flange member 210 of the beam 200 , and may be made of the same material as the beam 200 .

Referring to FIGS. 2 and 3 , the stiffener 300 is joined at the end of the beam 200 in the width direction D1 , and the first stiffener 310 and the third stiffener 330 in a direction away from the column 100 . ), the second stiffener 320 may be continuously formed.

The bonding structure of the present invention may be configured such that a plastic hinge occurs in the longitudinal direction D2 of the second stiffener 320 of the stiffener 300 .

In this way, the bonding structure induces a plastic hinge to occur in the longitudinal direction (D2) region of the second stiffener 320 of the stiffener 300 to prevent brittle fracture occurring in the end region of the beam 200, thereby improving ductility. It has the effect of improving and increasing strength.

An end of the first stiffener 310 in the longitudinal direction (D2) may be joined to the pillar 100, and an end of the first stiffener 310 in the width direction (D1) may be joined to an end of the flange member 210 in the width direction (D1).

The second stiffener 320 may have an end in the longitudinal direction (D2) in contact with the first stiffener 310 and an end in the width direction (D1) may be joined to an end in the width direction (D1) of the flange member 210 .

The third stiffener 330 has one end in contact with the first stiffener 310 in the longitudinal direction (D2) and the other end in contact with the second stiffener 320 in the width direction (D1), and the end in the width direction of the flange member 210 in the width direction (D1). (D1) can be joined to the end.

The joint structure of the present invention installs the stiffener 300 at the joint portion of the column 100 and the beam 200, so that the stress concentrated at the end of the beam 200 that is welded to the column 100 is transferred to a wider area. By dissipating, the generation position of the hinge of the plastic hinge is in the longitudinal direction (D2) region of the second stiffener 320 of the stiffener 300 in the end region of the beam 200, which is the joint portion of the column 100 and the beam 200. can be moved to

Of course, other additional components other than the first stiffener 310 , the second stiffener 320 , and the third stiffener 330 may be added to the stiffener 300 .

Referring to FIG. 2, before explaining the formulas (1) to (7) related to the design process for achieving the performance goal of the joint structure of the present invention and the retention strength review of the joint structure, the related variables are defined as follows. same.

Here, M pA : total plastic moment of section A, M pB : total plastic moment of section B, M pC : , total plastic moment of section C, L: length of beam 200 (L), L _S : stiffener 300 Length, L _S1 : the sum of the length of the first stiffener 310 and the length of the third stiffener 330, L _S2 : the length of the second stiffener 320, b _a : the width of the second stiffener 320, b _n : the width of the first stiffener 310, t _f is the thickness _{of the flange member 210 of the beam 200, b f} : the width of the flange member 210 of the _{beam 200, b af} : the beam 200 sum of the width of the flange member 210 and the width of the pair of second stiffeners 320, b _nf : the width of the flange member 210 of the beam 200 and the width of the pair of first stiffeners 310 sum of, d _a : the length of the first stiffener 310, d _b : the sum of the lengths of the second stiffener 320 and the third stiffener 330, t _f : the flange member 210 of the beam 200 Thickness, tw: the thickness of the web member 230 of the beam 200, h: the dance (height) of the beam 200, b _cf : the width of the column flange 110 of the column 100.

The bonding structure of the present invention may satisfy the following Equations (1) and (2).

Equation (1):

Equation (2):

Here, L _S : the length of the stiffener, h: the dance (height) of the beam, b _a : the width of the second stiffener 320, t _f : the thickness of the flange member 210 of the beam 200.

Referring to FIG. 2 , Equations (1) to (2) related to the design process for achieving the performance target of the bonding structure of the present invention will be described as follows.

According to Equation (1), the length (L _S ) of the stiffener should be formed to be more than 1.2 times the dance (h) of the beam.

According to Equation (1), the length of the stiffener (L _S ) is formed to be more than 1.2 times the dance (h) of the beam, the length of the stiffener (L _S ) is less than 1.2 times the dance (h) of the beam This is because the plastic hinge may not occur in the region of the second stiffener 320 in the case of .

According to Equation (2), the width b _a of the second stiffener 320 should be formed to be greater than or _{equal to the thickness t f} of the flange member 210 of the beam 200 . This is to generate a plastic hinge in the area of the second stiffener 320 .

_{This is because, when the width b a} of the second stiffener 320 is excessively narrowed, the plastic hinge may not occur in the region of the second stiffener 320 .

That is, when the bonding structure of the present invention satisfies Equations (1) to (2), the preferred bonding structure of the present invention for generating a plastic hinge in the longitudinal direction (D2) region of the second stiffener 320 It can satisfy the design to achieve the performance goal of

More preferably, the bonding structure of the present invention may satisfy the following Equations (1-1) and (2-1) instead of Equations (1) and (2).

Equation (1-1):

Equation (2-1):

According to Equation (2-1), the length (L _S ) of the stiffener should be formed to be at least 1.2 times the dance (h) of the beam, and the length (LS _S ) of the stiffener is 1.5 times the dance (h) of the beam should be formed below.

The length (L _S) is the reason for forming more than 1.2 times the beam dancing (h) of, the length (L _S) of the stiffener of the stiffener is if less than 1.2 times the beam dancing (h) of the second stiffener ( This is because the plastic hinge may not occur in the region of 320).

The reason that the length (L _S) of the stiffener is formed from more than 1.5 times the beam dancing (h) of the second stiffener (300) in the area, but the plastic hinges can be generated, to the unnecessary portion of the stiffener 320 extends Because there is a problem that is formed.

According to Equation (2-2), the width b _a of the second stiffener 320 should be formed to be greater than or _{equal to the thickness t f} of the flange member 210 of the beam 200, and the second stiffener 320 ) of the width (b _a ) should be formed to be less than twice _{the thickness (t f} ) of the flange member 210 of the beam 200 .

_{The width b a} of the second stiffener 320 should be greater than or _{equal to the thickness t f} of the flange member 210 of the beam 200 . This is to generate a plastic hinge in the area of the second stiffener 320 .

_{This is because, when the width b a} of the second stiffener 320 is excessively narrowed, the plastic hinge may not occur in the region of the second stiffener 320 .

_{The reason why the width b a} of the second stiffener 320 is _{not more than twice the thickness t f} of the flange member 210 of the beam 200 is that the plastic hinge in the area of the second stiffener 320 is may occur, but there are problems such as overdesign.

The bonding structure of the present invention may satisfy the following Equations (3) and (4).

That is, the bonding structure of the present invention can satisfy all of Equations (1) to (4).

Equation (3):

Equation (4):

Here, b _n : the width of the first stiffener 310, b _f : the width of the flange member 210 of the beam 200, d _a : the length of the first stiffener 310.

Referring to FIG. 2, Equations (3) to (4) related to the design process for achieving the performance target of the joint structure of the present invention will be described as follows.

According to Equation (3), the length d _a of the first stiffener 310 should be formed to be 0.5 times or more of _{the width b f} of the flange member 210 of the beam 200 .

A first stiffener (310) length (d _a), the reason for forming more than 0.5 times the width (b _f) of the flange member 210 of the beam 200, a first stiffener (310) length (d _a of the _{) is less than 0.5 times the width b f} of the flange member 210 of the beam 200, the _{length d a} of the first stiffener 310 is excessively shortened and the length of the second stiffener 320 is This is because plastic hinges may not occur in the area.

According to Equation (4), the width b _n of the first stiffener 310 should be 1/3 or more of _{the width b f} of the flange member 210 of the beam 200 .

This is, when the width b _{n of the first stiffener 310 is less than 1/3 times the width b f} of the flange member 210 of the beam 200, the width of the first stiffener 310 is This is because the plastic hinge may not occur in the region of the second stiffener 320 as (b _{n ) becomes excessively narrow.}

The present invention additionally satisfies Equations (3) and (4) along with Equations (1) and (2), so that the stiffener 300 is concentrated on the end of the beam 200 which is a weld joint with the column 100 The second stiffener of the stiffener 300 ( 320) in the longitudinal direction (D2) region.

That is, the bonding structure of the present invention is a more preferable bonding structure of the present invention for generating a plastic hinge in the longitudinal direction (D2) region of the second stiffener 320 when Equations (1) to (4) are satisfied. It can satisfy the design to achieve the performance goal of

More preferably, the bonding structure of the present invention may satisfy the following Equations (3-1) and (4-1) instead of Equations (3) and (4).

Equation (3-1):

Equation (4-1):

According to Equation (3-1), the length d _a of the first stiffener 310 should be formed to be 0.5 times or more of _{the width b f} of the flange member 210 of the beam 200, and the beam ( 200) of the flange member 210 of the width (b _f ) should be formed to be less than 0.75 times.

A first stiffener (310) length (d _a), the reason for forming more than 0.5 times the width (b _f) of the flange member 210 of the beam 200, a first stiffener (310) length (d _a of the _{) is less than 0.5 times the width b f} of the flange member 210 of the beam 200, the _{length d a} of the first stiffener 310 is excessively shortened and the length of the second stiffener 320 is This is because plastic hinges may not occur in the area.

A first stiffener (310) length (d _a), the reason for forming more than 0.75 times the width (b _f) of the flange member 210 of the beam 200, a first stiffener (310) length (d _a of the _{) is greater than 0.75 times the width b f} of the flange member 210 of the beam 200, plastic hinges may occur in the area of the second stiffener 320, but there are problems such as overdesign. am.

According to Equation (4-1), the width b _n of the first stiffener 310 should be 1/3 or more of _{the width b f} of the flange member 210 of the beam 200, _{The width b n} of the first stiffener 310 should be less than or equal to _{the width b cf} of the column flange 110 of the column 100 .

This is, when the width b _{n of the first stiffener 310 is less than 1/3 times the width b f} of the flange member 210 of the beam 200, the width of the first stiffener 310 is This is because the plastic hinge may not occur in the region of the second stiffener 320 as (b _{n ) becomes excessively narrow.}

When the width (b _{n ) of the first stiffener 310 exceeds the width (b cf} ) of the column flange 110 of the column 100 , the first stiffener 310 is welded to the column flange 110 . This is because there are problems such as over-design as it is installed even in areas where there is no joint.

The bonding structure may satisfy the following Equations (5) to (7) so that the plastic hinge is generated in the longitudinal direction D2 region of the second stiffener 320 .

Equation (5):

,

Equation (6):

,

,Equation (7):

,

Referring to FIG. 2, before describing Equations (5) to (7) related to the design process for achieving the performance target of the joint structure of the present invention, related variables are defined as follows.

Here, M pA : total plastic moment of section A, M pB : total plastic moment of section B, M pC : , total plastic moment of section C, L: length of beam 200 (L), L _S : stiffener 300 Length, L _S1 : the sum of the length of the first stiffener 310 and the length of the third stiffener 330, L _S2 : the length of the second stiffener 320, b _a : the width of the second stiffener 320, b _n : the width of the first stiffener 310, t _f is the thickness _{of the flange member 210 of the beam 200, b f} : the width of the flange member 210 of the _{beam 200, b af} : the beam 200 sum of the width of the flange member 210 and the width of the pair of second stiffeners 320, b _nf : the width of the flange member 210 of the beam 200 and the width of the pair of first stiffeners 310 sum of, d _a : the length of the first stiffener 310, d _b : the sum of the lengths of the second stiffener 320 and the third stiffener 330, t _f : the flange member 210 of the beam 200 Thickness, tw: the thickness of the web member 230 of the beam 200, h: the dance (height) of the beam 200.

Referring to Table 1, the IHS design result for the cross section (PH- 1000x300x16x25) of the beam 200 is as follows.

Here: the dance (h) of the beam 200 = 1000 mm, the width (b _f ) of the flange member 210 of the beam 200 = 300 mm, the thickness of the web member 230 of the beam 200 (t _w ) = 16 mm, the thickness of the flange member 210 of the beam 200 (t _f ) = 25 mm.

In the bonding structure of the present invention, when Equations (5) to (7) are satisfied, plastic hinges may occur in the longitudinal direction (D2) region of the second stiffener 320 .

Equation (5):

,

Equation (6):

,

Using Table 1 and Equation (6), the total plastic moment of section A is calculated as follows.

,Equation (7):

,

Using Table 1 and Equation (7), the total plastic moment of section B is calculated as follows.

The total plastic moment of section C is calculated as follows.

By Equations (5) to (7), whether the plastic hinge occurs in the longitudinal direction (D2) region of the second stiffener 320 is examined as follows.

Equation (5):

That is, by verifying the plastic hinge expression point using Equation (5), it was found that the plastic hinge occurred in the longitudinal direction (D2) section of the second stiffener 320 having a B section.

Referring to FIG. 2 , the beam 200 has an entire section in the width direction D1 of the pair of flange members 210 and an entire section in the height direction of the web member 230 in contact with the column 100 . It can be welded in the state.

The joint structure of the present invention does not form a scallop (S), which is a cut space for the convenience of welding, in the beam 200, and the entire end of the beam 200 and the stiffener 300 in the column 100 direction is It can be welded in a state in contact with the outer surface of the column (100).

That is, the beam 200 applied to the bonding structure of the present invention is not formed with a cut-out scallop (S) on the web member 230 , and the entire height direction cross-section of the web member 230 is welded to the column 100 . can be

Conventionally, as shown by the dotted line in the enlarged part of FIG. 2 , when the column 100 and the beam 200 are welded together, the web of the beam 200 is joined to the column 100 for convenience of welding. A method of welding and joining the column 100 and the beam 200 by forming the scallop (S), which is an open part at the end of the , was mainly used.

The scallop (S) is formed in an open portion at the point where the flange of the beam 200, the column 100, and the web meet, and the web of the beam 200 may be curvedly cut and formed.

However, when the column 100 and the beam 200 are welded to each other by forming the scallop S as in the prior art, stress is concentrated in the end region of the beam 200, which is the joint portion of the column 100 and the beam 200. As this occurred, brittle fractures occurred frequently.

Referring to the enlarged portion of Figure 2, the joint structure of the present invention, the width direction (D1) the entire section of the pair of flange members 210 of the beam 200, and the entire height direction of the web member 230 As the section is welded in a state in contact with the column 100, the conventionally introduced scallop (S) portion is excluded, thereby smoothing the flow of stress in the end region of the beam 200 to the column 100 and the beam ( 200) has the effect of improving the deformability by increasing the ductility at the joint portion and preventing the brittle fracture that has frequently occurred when the conventional scallops (S) are introduced.

The pillar 100, the beam 200, and the stiffener 300 may be welded, and preferably, the full penetration welding method may be applied to the pillar 100, the beam, and the stiffener 300 for welding.

2 and 3 , the stiffener 300 may be formed at both ends of the flange member 210 in the width direction D1, respectively.

The joint structure of the present invention is not the main purpose of simply reinforcing the end of the joint portion of the column 100 and the beam 200 to increase the bearing strength, but rather the stress generated at the end of the joint portion by inducing the generation of plastic hinges. For the purpose of preventing brittle fracture by dissipating to a wider area, the stiffener 300 may be preferably formed at both ends of the flange member 210 in the width direction D1, respectively.

The stiffener 300 may have an end bonded to the column 100 in the longitudinal direction (D2) and an end bonded to the flange member 210 in the width direction (D1).

A pair of flange members 210 may be disposed at the junction of the column 100 and the beam 200 , and the stiffener 300 may be disposed at both ends in the width direction D1 of each flange member 210 . .

That is, when the beam 200 is composed of H-shaped steel, two stiffeners 300 are installed on the flange member 210 of the upper side of the H-beam 200 of the H-shaped steel beam, and 2 on the flange member 210 of the lower side. As the four stiffeners 300 are installed, four stiffeners 300 may be installed at one side junction of the pillar 100 and the beam 200 .

Of course, it may be considered to install the two stiffeners 300 on only one side of the flange member 210 of the upper side and the flange member 210 of the lower side of the beam 200 .

However, in this case, the joint portion does not perform ductile behavior as in the case of non-reinforcement of the joint portion of the column 100 and the beam 200, and brittle fracture may occur in the joint portion such as the weld portion of the column 100 and the beam 200. There is, respectively, the stiffener 300 is installed at both ends in the width direction (D1) of the flange member 210 of the upper side, and the stiffener 300 is respectively installed at both ends in the width direction (D1) of the flange member 210 of the lower side. It may be more preferable to install and install four stiffeners 300 at the junction of one side of the pillar 100 and the beam 200 .

2 and 3 , the third stiffener 330 has an arc-shaped curved line whose cross section decreases from the first stiffener 310 toward the second stiffener 320 is formed, and the curved line may be formed in the entire length direction D2 of the third stiffener 330 .

Referring to FIG. 3 , a value of the radius R1 of the curved line of the third stiffener 330 may be the same as the length of the third stiffener 330 .

Referring to FIGS. 5A to 10B , a test result using a test specimen having a junction structure according to an embodiment of the present invention will be described as follows.

First, a large-scale experiment was performed to verify the joint structure of the present invention, the member used for the column 100 is PH-600x600x50x70 as Pos-H, and the member used for the beam 200 is also PH with Pos-H -1000x300x16x25, a T-shaped joint structure test specimen was manufactured, and the repeated loading procedure presented in KDS2019 was applied for the loading method.

5A is a view showing a test object according to an embodiment of the joint structure of the beam 200 and the column 100 according to an embodiment of the present invention, and FIG. 5B is a before and after experiment using the test object according to FIG. 5A. is a diagram showing

Referring to FIG. 5b, it behaved up to 0.05 rad 2cycle, and the deformation of 0.06 rad exceeded the actuator force range and the experiment was terminated.

A brittle fracture did not occur until the end of the loading, and a plastic hinge occurred in the second stiffener 320 portion of the stiffener 300 .

FIG. 6 is a diagram illustrating a relationship between a moment-rotation angle (maximum deformation angle) according to an experiment performed by the test object of FIG. 5A.

Referring to FIG. 6 , the specimen of the joint structure according to an embodiment of the present invention exhibited performance of 0.8 Mp or more at 0.04 rad based on the rotation angle (maximum deformation angle), thereby exhibiting the performance of the special moment joint.

That is, the test specimen of the joint structure of the present invention satisfies the special moment frame (SMF) performance by securing 80% or more of the preservative plastic moment (Mp) until it behaves 0.04 rad based on the rotation angle (maximum deformation angle) of the joint structure. knew what to do

FIG. 7 is a diagram illustrating a relationship between a moment and a plastic rotation angle according to an experiment performed by the test object of FIG. 5A.

Referring to FIG. 7 , the test specimen having a joint structure according to an embodiment of the present invention exhibited a performance of 0.8 Mp or more at 0.03 rad based on a plastic rotation angle, thereby exhibiting the performance of a special moment joint.

That is, it was found that the specimen of the joint structure of the present invention satisfies the special moment frame (SMF) required performance by securing at least 80% of the plastic moment of preservation (Mp) until it behaves 0.03 rad based on the plastic rotation angle.

6 and 7, the specimen of the joint structure of the present invention satisfies the performance of 0.8 Mp or more at 0.04 rad based on the rotation angle (maximum deformation angle), and satisfies the performance of 0.8 Mp or more at 0.03 rad based on the plastic rotation angle. It was found that the performance of the special moment joint was exhibited.

8 is a view showing the tensile strain for each section according to the experiment by the test specimen of FIG. 5A, and FIG. 9 is a view showing the tensile strain for each section of 0.05 rad of FIG.

8 and 9 show the length (L) direction (D2) and the width direction (D1) of the beam 200 by attaching strain gauges three at a time to measure the plastic deformation of the beam (200).

Referring to FIG. 8 , looking at the measured values of three strain gauges in the length (L) direction (D2) of the beam 200, the measured values of the strain gauge on the left and the strain gauge on the right are yield strain (Yield Strain) It was found that plastic deformation did not occur in this part in an elasticized state as it did not significantly deviate from the value of 0.002.

On the other hand, it was found that plasticization was performed while greatly deviating from 0.002, which is the value of the central strain gauge in the longitudinal direction (D2), among the three strain gauges in the length (L) direction (D2) of the beam 200.

That is, it was found that the plastic hinge was induced while plasticizing was performed in the longitudinal direction (D2) region of the second stiffener of the stiffener 300 in the specimen having the bonding structure of the present invention.

In FIG. 9 , the plastic deformation of the beam 200 was measured by attaching a strain gauge at three intervals in the width direction D1 of the beam 200 .

Referring to FIGS. 9 and 10B , the values of the tensile strengths of the left and right regions of the beam 200 in the width direction are different, which shows the highest strain rate in the second stiffener 320 of the stiffener 300 and is plastic This is because the hinge occurred.

10A and 10B are diagrams illustrating a finite element analysis process for analytical performance verification of the joint structure of the beam 200 and the column 100 according to an embodiment of the present invention.

Figure 10a shows the state of the finite element analysis before plastic deformation occurs in the specimen of the joint structure of the present invention, and Figure 10b shows the state of the finite element analysis after plastic deformation occurs in the specimen of the joint structure of the present invention. will be.

Also, referring to FIG. 10B , it can be seen that the plastic deformation state of the left region and the right region of the beam 200 in the width direction is different.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible within the scope without departing from the technical spirit of the present invention described in the claims. It will be apparent to those of ordinary skill in the art.

1: Column 2: Beam
3: End reinforcement plate 4: Brittle fracture part
100: column 110: column flange
120: pole web 130: horizontal reinforcing plate
200: beam 210: flange member
230: web member 300: stiffener
310: first stiffener 320: second stiffener
330: third stiffener D1: width direction
D2: longitudinal S: scallop
L: Length of beam L _S : Length of stiffener
L _S1 : sum of the length of the first stiffener and the length of the third stiffener
L _S2 : Length of the second stiffener b _a : Width of the second stiffener
b _n : the width of the first stiffener t _f is the thickness of the flange member of the beam
tw: thickness of web member of _{beam b f} : width of flange member of beam
b _af : sum of the width of the beam flange member and the width of the pair of second stiffeners
b _nf : sum of the width of the beam flange member and the width of the pair of first stiffeners
d _a : length of the first stiffener
d _b : the sum of the lengths of the second stiffener and the third stiffener
t _f : thickness of flange member of beam h: dance (height) of beam

Claims (7)

Pillar;
A beam having an end joined to the column, a pair of flange members facing each other, and a web member connecting between the pair of flange members; and,
Including; stiffener installed at the joint portion of the column and the beam;
The stiffener is
a first stiffener joined to the pillar and the flange member and having a relatively large width;
a second stiffener joined to the flange member and having a relatively smaller width than the first stiffener of the beam; and,
and a third stiffener formed between the first stiffener and the second stiffener and having a curved line whose cross section decreases from the first stiffener toward the second stiffener is formed;
A plastic hinge is generated in the longitudinal region of the second stiffener,
A joint structure of a column and a beam, characterized in that it satisfies the following equations (1), (2), (3), (4).

Equation (1):

Equation (2):

Here, LS: the length of the stiffener, h: the dance (height) of the beam, ba: the width of the second stiffener, tf: the thickness of the flange member of the beam.

Equation (3):

Equation (4):

Here, bn: the width of the first stiffener, bf: the width of the flange member of the beam, da: the length of the first stiffener.
delete delete According to claim 1,
A joint structure between a column and a beam, characterized in that the following equations (5) to (7) are satisfied so that a plastic hinge is generated in the longitudinal region of the second stiffener.

Equation (5):

Equation (6):

,

Equation (7):

,

Here, M pA : total plastic moment of section A, M pB : total plastic moment of section B, M pC : , total plastic moment of section C, L: length of beam, L _S : length of stiffener, L _S1 : length of first stiffener The sum of the length and the length of the third stiffener, L _S2 : Length of the second stiffener, b _a : Width of the second stiffener, b _n : Width of the first stiffener, t _f is the thickness of the flange member of the beam, b _f : Width of the flange member of the beam, b _af : the sum of the width of the flange member of the beam and the width of the pair of second stiffeners, b _nf : the sum of the width of the flange member of the beam and the width of the pair of first stiffeners, d _a : the length of the first stiffener, d _b : the sum of the lengths of the second stiffener and the third stiffener, t _f : the thickness of the flange member of the beam, h: the dance (height) of the beam.
5. The method of claim 1 or 4, wherein the
A joint structure of a column and a beam, characterized in that the entire section in the width direction of the pair of flange members and the entire section in the height direction of the web member are welded in contact with the column.
According to claim 1 or 4, wherein the stiffener,
A joint structure of a column and a beam, characterized in that formed at both ends in the width direction of the flange member.
According to claim 1 or 4, wherein the third stiffener,
An arc-shaped curved line whose cross section decreases from the first stiffener to the second stiffener is formed, and the curved line is formed over the entire longitudinal direction of the third stiffener.

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