JPH0833026B2 - Steel material for steel structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a ridge material of a steel structure, and more particularly to a ridge material such as a long steel pipe forming a ridge structure. .

[Conventional technology]

Using many steel components such as long H-section steel,
Large three-dimensional structure When a steel structure such as a building is constructed, the steel structure that receives a horizontal force due to a dynamic load such as an earthquake is attached with a slanting material in an oblique posture that absorbs the energy of the horizontal force. It is often the case that the ends are integrated into the four corners of the upper, lower, left and right sides of the steel frame of each room, which is the unit compartment of each floor. For example, Jitsuko Sho 42-22
Japanese Patent No. 992, etc. proposes a structural member similar to a streak material applied to such a structure.

[Problems to be Solved by the Invention]

By the way, when a steel structure whose yield strength is determined by a dynamic load applied by the occurrence of an earthquake or the like is to be designed with a streak structure, for example, the horizontal force that the steel structure faces from left to right [first See force P in the figure],
Out of the set of timbers, the upper left corner C ₁ and the lower right corner C ₄
A compressive force acts on one side of the timber that connects to and, and a tensile force acts on the other side that connects the upper right corner C ₂ and the lower left corner C ₃ . When the compression strand material that receives the compression force buckles, its yield strength decreases sharply as shown by the broken line, as shown in FIG. However, the tensile-sheathed material on the other side plastically deforms even after yielding while maintaining the proof stress R _t as shown by the solid line.

The total yield strength of a pair of glazed members is as shown by the one-dot chain line, but due to buckling of the compression glazed member, plastic deformation occurs while leaving the yield strength R _t of the tension glazed member. Therefore, by maintaining the total proof stress shown by the chain double-dashed line in the figure and deforming the set of strand materials, the compression strand material becomes
It will be designed with oversized dimensions to provide an elastic response that is sufficiently safe against buckling. In other words, in the design of such a compression strand material, a considerably large design stress is assumed as compared with the case of utilizing plastic deformation, so that the compression strand material becomes a large material that can respond elastically, and it is extremely uneconomical design. There is a problem that becomes.

Furthermore, in the event of an earthquake, a large amount of stress will be exerted on the compression ridge material that retains the elastic region as described above, and it will also cause an extremely large amount of stress on adjacent columns and beams. However, it often happens that it becomes a problem in design practice.

There is also a method of designing by evaluating the post-buckling proof stress of the compression strand material, but it is not possible to properly evaluate the rapid decrease in proof stress after buckling to give the required seismic performance to the steel structure. At present it is not easy.

FIGS. 14 (a) and 14 (b) schematically show the deformation of the steel structure when buckling does not occur when an external force is applied and when it does. In these cases, the superiority or inferiority of the seismic resistance is discussed by the magnitude of the energy consumption (hatched area A and B in the figure) generated by the deformation. Since the consumed energy is larger in Fig. 14 (b), which is plastically deformed, the earthquake resistance is higher than that in Fig. 14 (a). Further, since the elastic proof strength is larger in Fig. 14 (a), there is a problem that a vicious cycle occurs in which the response stress due to the earthquake becomes larger.

With the conventional thin structure, buckling is inevitable, so
It was considered impossible to obtain the properties shown in Fig. 14 (b). On the other hand, as a structural type that gives the properties as shown in FIG. 14 (b), there is a ramen structure without a thin material.
However, there is a problem that a large amount of steel material needs to be input because the lateral deformation is much larger than that of the bare structure.

The present invention has been made in view of the above problems, and an object thereof is to devise a streak member integrated with a structural member of a steel structure, and by providing a thin portion in the vicinity of its end, The purpose is to obtain the properties shown in FIG. 14 (b). And, compared with the conventional design, the amount of steel used is reduced to improve economic efficiency, and at the time of a large-scale earthquake, stable plastic deformation is achieved with a desired yield strength, and a large earthquake resistance is imparted to the steel structure. The purpose is to provide a timber that can be used.

[Means for solving the problem]

INDUSTRIAL APPLICABILITY The present invention, as shown in FIGS. 1 and 2, is applied to a streak member whose ends are integrated with a joint between a horizontal member and a vertical member. The feature is that the streak member 1 is formed of a pipe material and is arranged in a cross shape through a spherical node member 2, and the streak member 1 has a spherical node member 2 as a boundary. At least one thin portion 3, 3 is formed on each of the one side and the other side. All thin parts 3,3
As plastic deformation with a small external force than the buckling strength of the bracing member, the inside diameter is that is identical to the pipe-shaped bracing member 1 has a thickness t ₁ outer diameter is small.

[Action]

When, for example, the horizontal force P shown in the figure is applied to a steel structure to which a pair of strand members 1 is attached, a compression strand member 1A
The compressive force is applied to and the tensile force is applied to the tensile strand material 1B. A wall thickness t ₁ having the same inner diameter as the pipe-shaped strand member 1 but a small outer diameter on each of the one side and the other side of the spherical node member 2 joining the strand members ₁ Thin part 3
Is provided so as to be plastically deformed by an external force smaller than the buckling resistance of the stiffener 1. Therefore, the thin portion 3 yields first and locally buckles [see the broken line in FIG. 3].
However, the energy transmitted to the shining material 1 due to the earthquake is absorbed by the thin portion 3 which locally buckles and plastically deforms while expanding outward, and the remaining energy is radiated to the outside as heat. Then, the streak material 1 having the thin portion 3 and receiving the compressive force is plastically deformed while maintaining the yield strength, and the streak material 1 receiving the tensile force is also plastically deformed after yielding and absorbs the energy of the external force. can do. As a result, it is possible to avoid a drastic decrease in the proof stress due to the buckling of the sliding member 1 that receives the compressive force, and to prevent the building from collapsing.

〔The invention's effect〕

According to the present invention, the pipe-shaped thin-walled portion, which is thinner than the thickness of the pipe-shaped ribbed material formed at the end, yields before the compression ribbed material that receives the compressive force buckles, and the yield strength is maintained. However, it tends to be axially symmetric and plastically deformed in a large ratio in the direction of the applied force. As a result, the external force as shown in Fig. 14 (b)
In the case of P _{1, in} the case of a medium-scale earthquake, the thin wall does not buckle and the thin-walled part is deformed within the elastic range, and in the case of a large-scale earthquake in the case of external force P ₂ , the wall does not buckle It can be designed to yield the thin section that is part of the timber. Moreover, since the thin-walled portion after yielding maintains the proof stress, it is possible to impart greater seismic resistance to the steel structure by plastic deformation of the thin-walled portion of the streak material as compared with the conventional case.
Further, the node member is spherical, and not only is it easy to join the pipe-shaped streak members, but also the thin-walled portions on the one side and the other side with the node member as a boundary are easily and reliably deformed. Then, the plastic material is allowed to be downsized, so that the downsizing material can be downsized, and the amount of steel material used in the steel structure formed in the downsizing structure can be reduced. The inner diameter of each of the thin portions is the same as that of the pipe-shaped streak member, but the outer diameter is small, and the thin portions can be easily formed.

〔Example〕

Hereinafter, the present invention will be described in detail based on examples.

Fig. 1 is an external view of the structural members that make up a steel structure with a slender structure. The four slender members 1 that are long steel pipes in the figure are the vertical members 4A and the horizontal members 4B of the structural member 4. it is a junction of the four corners C ₁ -C _4, are integrated by welding to the joint member 2 spherical to form a brace structure. The structural member 4 of this example is a column 4A and a beam 4B of a steel structure such as a building shown in FIG.
And is surrounded by the columns 4A and the beams 4B on each floor to form one section. And the beam 4B is the pillar 4A which is erected.
It is integrated by welding.

By the way, the horizontal force P of the arrow on the structural member 4 due to the earthquake
When [see FIG. 1] acts, for example, the upper left corner
Compression brace material 1A extending from C ₁ is, so as not separated from the structural member 4, its end is integrated by welding in the corners C _1. By the way, stiffeners 5a and 5b, which are reinforcing plate members for reinforcing the base metal, are attached to the welding points of the compression rib material 1A on the columns 4A and the beams 4B forming the corner C ₁ [see Fig. 2]. Further, the stiffener 5c is also attached to the welding points of the pillar 4A and the beam 4B, which are integrated with each other. As shown in FIG. 1, other corners of the structural member 4
The stiffeners 5a to 5c are also fixed to the structural member 4 side at the welded portions of the ends of the compression streak material 1A and the tensile streak material 1B integrated with C _{2 to} C ₄ .

On the other hand, the corner of the steel pipe compression strand material 1A [see Fig. 2]
A thin portion 3 having a length 1 extending in the axial direction, which is the pressing direction, is provided at the end (not shown) on the C ₁ side or the corner C ₄ side. That is, the thin portion 3 has a thickness t of the compression strand material 1A.
It is formed into a thin wall having a length l, which is formed by encircling a thinner wall thickness t ₁ all around. Incidentally, the corners C ₂ or corners C ₃ tensile bracing member 1B similarly thin-walled portion 3 extending from is provided. The thin-walled pipe body having the thin-walled portion 3 has a compression line when the streak member 1 or the structural member 4 having the thin-walled portion 3 is within the elastic range when a large external force acts, such as during a large earthquake. The thin portion 3 of the paddle material 1A yields first, and is plastically deformed while maintaining the proof stress (see FIG. 3).

In addition, a nodal member 2 in which one end of the streak member 1A extending from the corner C ₁ of the structural member 4 is integrated by welding or the like.
[Refer to FIG. 4] is a hollow spherical body which is easy to join pipe materials, and a hollow hollow ball joint which is a through-pipe type joint is adopted. In this example, the streak member 1 whose ends are integrated with the corners C _{1 to} C ₄ of the structural member 4 of FIG.
Among them, the tensile strand material 1B is a single steel pipe and penetrates the hole 2a for insertion of the node member 2 (see FIG. 5), while the penetration part and the periphery of the hole 2a are integrated by welding. Also, the compression strand material 1A extending from the corner C ₄ is also integrated with the nodal member 2 by welding. The penetrating material 1 that penetrates may be the compressing material 1A, on the contrary. Instead of the above-mentioned hollow ball having a hole, an octaplate joint which is a non-penetrating joint, although it is a similar hollow sphere, may be used [see FIG. 6].

In the case where the thin portion 3 (see FIG. 3) of the thin material 1 which is a feature of the present invention is formed to be a thin portion having a length l, it is machined to a required thickness t ₁ and the portion other than the thin portion 3 is formed. The thin-walled portion 3 is made plastic by an external force smaller than the buckling resistance. The wall thickness t ₁ can be easily determined by using the finite element method or the like to determine the proof stress of the ribbed material 1. Then, by selection based on that, the plastic deformation amount of the thin portion 3 is appropriately processed.

When a part of the thin material 1 is thinned in this way, the thin pipe body behaves as follows. That is, in the structural member 4 having a slender structure in which the node member 2 which is a hollow hollow ball joint or octaplate joint is used, when the horizontal force P due to a large-scale earthquake acts, it is shown in FIG. As described above, in the thin wall portion, outward bulging which is the local buckling portion 6 (so-called lantern buckling portion) occurs. Due to the occurrence of the local buckling portion 6,
It is known that the compression strand material 1A plastically deforms while shrinking in the pressing direction without reducing the yield strength, and a steel structure assembled with the structural member 4 adopting such a strand structure is extremely convenient. Is good.

At the time of plastic deformation of compression line material 1A, tensile line material
Since the thin portion 3 of 1B plastically deforms in the elongation direction while maintaining a constant proof stress even if it yields, in the compression stirrup member 1A, plastic deformation in the shrinking direction which maintains the proof stress is promoted. It In this way, since the sled members 1 and the structural members 4 other than the thin portion 3 are set to be larger than the maximum proof stress of the thin portion 3, the steel structure adopting the slender structure causes a large-scale earthquake. When an external force is applied along with the above, only the local buckling portion 6 of the thin portion 3 is generated, and plastic deformation is performed without sharply reducing the proof stress, and the collapse of the steel structure that is the building is prevented.

The four streak members 1 shown in FIG. 7 are integrated with the nodal member 2 which is an octaplate joint, but the thin-walled portion 3 at the end on the side of the corners C _{1 to} C ₄ [see FIG. 1]. 〕In addition to,
A thin portion 7 is also provided in the vicinity of the end on the node member 2 side.
In this case, the sum of the length of the thin-walled portion 3 provided on the side of the corners C _{1 to} C _{4 of} each of the seam members ₁ and the length of the thin-walled portion 7 may be 1, for example, one of 2 / If the length is 3 l, the other is 1/3
It is selected as appropriate such as l. In this way, when two thin portions are provided in a distributed manner on one gleaming material 1,
Similar to the case where only the thin portion 3 described above is provided, even if a large-scale earthquake occurs, in the structural member 4 having a sled structure, two small bulges (local buckling parts) are formed in the sled member 1A. Only when it occurs, it is possible to plastically deform it without sharply reducing the yield strength.

Instead of the thin portion 3 shown in FIG. 2, as shown in FIG. 8, the corners of the compression strand material 1A having the end portions integrated with the corner portions C ₁ and C ₄ [see FIG. 1] are shown. Two thin portions 8, 8 may be provided at the ends on the side of the portions C ₁ , C ₄ . Then, the thin wall portions 8 and 8 are processed so that the wall thickness t ₁ thereof is thinner than the wall thickness t of the steel rod 1A, which is a steel pipe. While 1a is left, the length of the thin portions 8 and 8 is l / 2.

When a horizontal force P due to a large-scale earthquake acts, this corner
The thin-walled portions 8 and 8 close to C ₁ and the corner C ₄ have local bulges smaller than those of the local buckling portion 6 (see FIG. 2) in the thin-walled portion 3 having the length l. Bending parts 9 and 9 are generated [see FIG. 9]. Then, the steel pipe portion 1a serving as the reinforcing portion restrains the local buckling portions 9 and 9 from bulging outward so that it is extremely convenient for maintaining the proof stress of the thin portions 8 and 8. It should be noted that the thin-walled portions 8 and 8 are also provided in the short portions on the side of the corners C ₂ and C _{3 in the} tensile rib material 1B extending from the corners C ₂ and C ₃ [see FIG. 1]. Then, at the time of a large-scale earthquake, the compression glide material 1A in the structural member 4 having a glide structure can be plastically deformed while maintaining the required yield strength and being promoted by the tension glide material 1B.

In addition, the thin-walled portion 3 is formed close to the corners C _{1 to} C ₄ [see FIG. 1].
When the four rib members 1 provided with the thin wall portions 8 and 8 are applied to the structural member 4 constituting the steel structure, the compression buckle member 1A has a local buckling portion 6 [Fig. Local) and local buckling part 9,
9 (see Fig. 9) causes plastic deformation, and as shown in Fig. 10 (a) for the former and Fig. 10 (b) for the latter, horizontal force P ₁ is applied by a medium-scale earthquake. Even steel structures are limited to deformation in the elastic range. Horizontal force due to large-scale earthquake
When P ₂ acts, the former is shown in FIG. 10 (a) and the latter is shown in FIG.
As shown in Fig. 10 (b), the streak material 1 that maintains the proof stress.
It is possible to utilize the large plastic deformation of the steel, and it is possible to realize an ideal rib material in a steel structure. Further, the above-mentioned thin line material provided with the thin portion having different modes can be similarly adopted as the ideal thin line material.

In the iron structure shown in FIG. 12, in order to realize a large plastic deformation such as δ ₁ = h / 50 which is 1/50 of the floor height h, the horizontal plastic deformation amount δ ₁ shown in FIG. Is h = 3,50
If 0 mm, the plastic deformation amount δ _{1 at} that time is δ ₁ = 3,500
/ 50 = 70mm. The length L of the beam 4B in FIG. 1 is L = 7,000
Since the triangle abc is a right triangle, the length L ₁ of the tensile streak member without external force shown in FIG. 13 is 7,826 mm since it is mm. On the other hand, when the horizontal plastic deformation amount δ ₁ = 70 mm is realized, the length of the tensile rib material
L ₂ is 7,889 mm and δ = L ₂ −L ₁ ≈ 63 mm. And
As shown in FIG. 1, in a set of thin material 1 in which one thin portion 3 is formed, 10% of the compression plasticity of the length 1 of the thin portion 3 of the compression material 1A or the tensile material 1B is set. When the amount of deformation and the amount of tensile plastic deformation are allowed, 2l × 0.1
From = 63 mm, l = 315 mm is obtained. That is, when the thin portions 3 of l = 315 mm are formed on each of the four rib members 1 shown in FIG. 1, large plastic deformation such as δ ₁ = h / 50 is realized. Furthermore, a set of ridge members 1 having eight thin-walled portions 8 (see FIG. 8) having a length l = 157.5 mm.
Even in such a case, a desired large plastic deformation can be realized.

As described above, the rib material is made of a pipe material and is arranged in a cross shape with the node members interposed therebetween. At least one thin-walled part is formed on each of the one side and the other side of the ridged material with the node member as a boundary, and each thin-walled part is plastically deformed by an external force smaller than the buckling resistance of the ridged material. In addition, the inner diameter is the same as that of the pipe-shaped strand material, but the outer diameter is small. In this way, when the thin-walled portion is formed into a thin pipe shape, so-called lantern buckling that is axisymmetric in the thin-walled portion is exhibited and swelling due to external force occurs,
A large seismic resistance is imparted to the steel structure by causing plastic deformation while shrinking in the pressing direction without reducing the yield strength of the compression strand material. The thin-walled part has at least one thin-walled part on each side sandwiching a spherical nodal member that is easily joined to a pipe-shaped thin-belt material, so that the above behavior can be reliably obtained, and by extension, a thin-walled structure is formed. It is also possible to reduce the amount of steel material used in the steel structure. Further, the inner diameter of the thin portion is the same as that of the pipe-shaped streak member, but the outer diameter is small, so that the working and manufacturing for forming the thin portion are easy.

[Brief description of drawings]

FIG. 1 is an assembly drawing of structural members constituting a steel structure of a thin structure, FIG. 2 is an explanatory view of attachment of a compression sliding member and a structural member and a thin portion, and FIG. 3 is a local seat in the thin portion. FIG. 4 is a state diagram of the bent portion, FIG. 4 is an explanatory view of the attachment of the node member and a pair of slide members, FIG. 5 is a state diagram in which the slide member penetrates the insertion hole, and FIG. 6 is different. Fig. 7 is an explanatory view of the attachment of a type of nodal member and a set of sliding members, Fig. 7 is an explanatory view of a thin portion provided on the side of the nodal member, and Fig. 8 is a mounting of a compressing sliding member and a structural member and different FIG. 9 is an explanatory view of a thin portion, FIG. 9 is a state diagram of a local buckling portion in a different thin portion, and FIG. 10 (a) is a plastic deformation state diagram of a structural member having a thin member having a thin portion attached thereto. Figure (b) is a plastic deformation state diagram of a structural member to which a barbed material having different thin parts is attached, and Figure 11 is a conventional Plastic deformation state diagram of structural member with streaks attached, Fig. 12 is an illustration of steel structure formed by columns and beams and stiffeners, Fig. 13 is tensile streaks due to horizontal displacement of beams Fig. 14 (a) is a schematic diagram of the deformation of a steel structure without buckling when an external force is applied, and Fig. 14 (b) shows the buckling when an external force is applied. It is a deformation schematic diagram of the accompanying steel structure. 1 ... Shinkai material, 2 ... Nodal member, 1A ... Compression seam material, 1B ... Tensile seam material, 3,7,8 ... Thin wall part, t ₁ ...
… Thick.

Claims (1)

[Claims] 1. A streak member whose end is integrated with a joint between a horizontal member and a vertical member, wherein the stirrup member is formed of a pipe material and arranged in a cross shape through a spherical node member. , At least one thin-walled portion is formed on each of the one side and the other side of the gleaming member with the spherical nodal member as a boundary, and each thin-walled part has an external force smaller than the buckling resistance of the gleaming member. In order to be plastically deformed, the inner diameter of the steel structure is the same as that of the pipe-shaped ribbed material, but the outer diameter is small, which is a ribbed material of the steel structure part.