JP7351271B2 - Steel beams, column-beam joint structures, and structures containing them - Google Patents

Steel beams, column-beam joint structures, and structures containing them Download PDF

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JP7351271B2
JP7351271B2 JP2020134374A JP2020134374A JP7351271B2 JP 7351271 B2 JP7351271 B2 JP 7351271B2 JP 2020134374 A JP2020134374 A JP 2020134374A JP 2020134374 A JP2020134374 A JP 2020134374A JP 7351271 B2 JP7351271 B2 JP 7351271B2
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steel beam
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信太郎 金崎
隼平 安永
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JFE Steel Corp
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本発明は、鉄骨梁、柱梁接合構造およびこれを有する構造物に関する。 The present invention relates to a steel beam, a column-beam joint structure, and a structure having the same.

ラーメン構造等の構造物、例えば建築物においては、梁の材軸方向の端部、すなわち柱に接続される部分は、地震時の短期荷重作用時に大きな曲げモーメントを受ける。特に、鉄骨梁の場合には、地震力等の短期荷重作用時に曲げモーメントを受けると、材軸方向の端部のウェブやフランジに局部座屈が発生して、鉄骨梁の耐力や変形能力が急激に低下することがある。 In structures such as rigid frame structures, such as buildings, the ends of beams in the axial direction, that is, the portions connected to columns, receive a large bending moment when short-term loads are applied during earthquakes. In particular, in the case of steel beams, when they are subjected to bending moments during short-term loads such as earthquake forces, local buckling occurs in the webs and flanges at the ends in the axial direction, reducing the strength and deformation capacity of the steel beams. May decrease rapidly.

具体的には、鉄骨梁の材軸方向の端部において、ウェブが局部座屈したり、現場溶接の施工上の必要からウェブに設けられるスカラップ底からフランジが破断したり、鉄骨梁が柱に接合される溶接部が破断したりして、鉄骨梁の塑性変形能力が十分に発揮されずに、構造物に想定外の被害が生じる恐れがある。 Specifically, the web may buckle locally at the end of the steel beam in the axial direction, the flange may break from the scalloped bottom of the web due to on-site welding, or the steel beam may be joined to the column. The plastic deformation capacity of the steel beams may not be fully utilized, and unexpected damage may occur to the structure.

鉄骨構造物の塑性設計では、地震力等の短期荷重作用時に、鉄骨梁の材軸方向の端部が曲げモーメントを受けて塑性変形した後も、破断せずに大きく塑性変形可能な塑性ヒンジとなることにより、鉄骨梁が受けるエネルギーを吸収するように設計する。したがって、鉄骨梁が十分な塑性変形能力を発揮できるように、鉄骨梁の材軸方向の端部の局部座屈や早期破断を確実に防止する必要がある。 In the plastic design of steel structures, we use plastic hinges that can undergo large plastic deformations without breaking even after the ends of the steel beams in the axial direction receive bending moments and undergo plastic deformation during short-term loads such as earthquake forces. The steel beams are designed to absorb the energy received by the steel beams. Therefore, in order for the steel beam to exhibit sufficient plastic deformation ability, it is necessary to reliably prevent local buckling and early fracture at the ends of the steel beam in the axial direction.

また、建築物等の構造物においては、梁下の空間を有効に活用して階高を抑え、構造物の施工費用を低減するため、梁に設備配管や配線を通すための貫通孔が設けられることが多い。Ｈ形、Ｉ形、溝形等の断面を有する鉄骨梁に貫通孔が設けられる場合には、ウェブに貫通孔が設けられて断面欠損が生じることとなる。 In addition, in structures such as buildings, through-holes are installed in the beams to allow equipment piping and wiring to pass through, in order to effectively utilize the space under the beams to reduce the floor height and reduce construction costs. often. When a through hole is provided in a steel beam having an H-shaped, I-shaped, channel-shaped, etc. cross section, the through hole is provided in the web, resulting in a cross-sectional defect.

鉄骨梁のウェブに設けられる貫通孔は、ウェブの座屈耐力を低下させるため、ウェブの局部座屈が発生しやすくなり、鉄骨梁の塑性変形能力の低下の原因となる。このような局部座屈の発生を防ぐ観点から、地震力等の短期荷重作用時に大きな曲げモーメントを受ける、鉄骨梁の材軸方向の端部の塑性化領域に貫通孔を形成することは、一般的には避けるべきとされている。 The through holes provided in the web of the steel beam reduce the buckling strength of the web, making it easy for local buckling of the web to occur, which causes a decrease in the plastic deformation ability of the steel beam. From the perspective of preventing the occurrence of such local buckling, it is common practice to form through holes in the plasticized region of the axial ends of steel beams, which are subject to large bending moments during short-term loads such as earthquake forces. It is said that it should be avoided.

一方、例えば非特許文献１に開示されるように、鉄骨梁の材軸方向の端部に貫通孔を形成して、材軸方向の端部が曲げモーメントを受けるときに貫通孔の周囲のウェブが変形するようにすると、ウェブにより負担される耐力の急激な低下が抑えられて、鉄骨梁の塑性変形能力が向上する場合があることも知られている。このとき、貫通孔の位置におけるウェブの有効断面による全塑性耐力が、貫通孔の位置に作用する曲げモーメント以上となるように、貫通孔の大きさを設定することにより、貫通孔の位置の断面欠損に起因する鉄骨梁の耐力の低下の割合を抑えることができる。 On the other hand, as disclosed in Non-Patent Document 1, for example, a through hole is formed at an end in the axial direction of a steel beam, and when the end in the axial direction receives a bending moment, the web around the through hole is It is also known that if the web is made to deform, a sudden drop in the yield strength borne by the web can be suppressed and the plastic deformation ability of the steel beam may be improved. At this time, by setting the size of the through hole so that the total plastic strength due to the effective cross section of the web at the position of the through hole is greater than the bending moment acting on the position of the through hole, the cross section at the position of the through hole is It is possible to suppress the rate of decline in the strength of steel beams due to defects.

また、鉄骨梁のウェブに貫通孔が形成されるときの断面欠損に起因して、鉄骨梁の耐力や変形能力が低下することを防ぐため、貫通孔の周囲を補強することが広く行われている。鉄骨梁のウェブに形成される貫通孔の周囲の補強方法としては、図１６に示す鉄骨梁８Ａのように、貫通孔８３ｈの周囲のウェブ８３に、同様に貫通孔８８ｈを有するプレート８８を溶接する方法や、図１７に示す鉄骨梁８Ｂのように、貫通孔８３ｈの内周にリングまたはスリーブ管８９を挿入して接合する方法などが知られている。 Additionally, in order to prevent the strength and deformation capacity of steel beams from decreasing due to cross-sectional defects when through-holes are formed in the web of steel beams, it is widely practiced to reinforce the area around the through-holes. There is. As a method of reinforcing the area around the through hole formed in the web of the steel beam, as in the steel beam 8A shown in FIG. 16, a plate 88 having a through hole 88h is similarly welded to the web 83 around the through hole 83h. There are known methods such as a method of inserting a ring or a sleeve pipe 89 into the inner periphery of a through hole 83h and joining it, as in the case of a steel beam 8B shown in FIG. 17.

貫通孔の周囲を補強する必要性の有無は、貫通孔の位置における鉄骨梁の曲げ耐力およびせん断力と、貫通孔の位置に作用する曲げモーメントおよびせん断力の大きさとの大小関係から判断できる。特許文献１には、鉄骨梁の耐力を確保する上で、鉄骨梁のウェブに貫通孔を形成しても補強する必要のない材軸方向の範囲が開示されている。 Whether or not it is necessary to reinforce the area around the through hole can be determined from the magnitude relationship between the bending strength and shear force of the steel beam at the position of the through hole and the magnitude of the bending moment and shear force acting at the position of the through hole. Patent Document 1 discloses a range in the axial direction of the steel beam in which reinforcement is not required even if through holes are formed in the web of the steel beam in order to ensure the strength of the steel beam.

特許第３２３８５４０号公報Patent No. 3238540

難波尚、外１名、「梁ウェブ穿孔加工による角形鋼管に接合される梁の変形能力の改善」、鋼構造年次論文報告集、日本鋼構造協会、２００６年１１月、第１４巻、ｐｐ．６７３～６８０Takashi Namba and 1 other person, "Improvement of deformation ability of beams joined to square steel pipes by beam web perforation", Steel Structure Annual Paper Report, Japan Society of Steel Structures, November 2006, Vol. 14, pp. ．． 673-680

ここで、特許文献１では、鉄骨梁の材軸方向の先端からの距離が所定の条件を満たすような範囲を規定し、これを貫通孔を補強する必要のない材軸方向の範囲としており、この範囲外となる鉄骨梁の材軸方向の端部の塑性化領域では、図１６や図１７に示すような方法で貫通孔の周囲を補強している。 Here, in Patent Document 1, a range is defined such that the distance from the tip of the steel beam in the axial direction satisfies a predetermined condition, and this is defined as a range in the axial direction in which the through hole does not need to be reinforced, In the plasticized region at the end of the steel beam in the axial direction outside this range, the periphery of the through hole is reinforced by the method shown in FIGS. 16 and 17.

図１は、鉄骨梁の材軸方向の端部にかかる曲げモーメントＭと、鉄骨梁に生じる変形角θとの関係を、模式的に示すグラフである。図１中の実線は、貫通孔が設けられていない従来の鉄骨梁が、局部座屈や破断を生じることなく塑性変形能力を十分に発揮した場合を示す。このような場合では、鉄骨梁の耐力Ｍは、全塑性耐力Ｍｐに到達した後、緩やかな勾配で上昇を続けて最大耐力に到達し、その後は緩やかな勾配で下降して、再び全塑性耐力Ｍｐまで低下するような挙動を示す。図１に示した例では、鉄骨梁の耐力Ｍが全塑性耐力Ｍｐに到達した後、全塑性耐力Ｍｐ以上を維持できる変形角の上限はθ３である。この、全塑性耐力Ｍｐ以上を維持できる変形角θの上限が大きいほど、鉄骨梁の塑性変形能力が高い。 FIG. 1 is a graph schematically showing the relationship between the bending moment M applied to the end of a steel beam in the axial direction and the deformation angle θ generated in the steel beam. The solid line in FIG. 1 indicates a case where a conventional steel beam without through holes fully exhibits its plastic deformation ability without causing local buckling or fracture. In such a case, the strength M of the steel beam reaches the total plastic strength Mp, continues to rise at a gentle slope until it reaches the maximum strength, and then decreases at a gentle slope until it reaches the total plastic strength again. It shows a behavior that decreases to Mp. In the example shown in FIG. 1, after the proof stress M of the steel beam reaches the total plastic proof stress Mp, the upper limit of the deformation angle that can maintain the total plastic proof stress Mp or more is θ3. The larger the upper limit of the deformation angle θ that can maintain the total plastic proof stress Mp or more, the higher the plastic deformation ability of the steel beam.

しかし、鉄骨梁の材軸方向の端部が曲げモーメントを受けて変形角θが増加していき、全塑性耐力Ｍｐを超えた後、図１中に×印で示すように、変形角θがθ１のときに材軸方向の端部が破断すると、この時点で鉄骨梁の塑性変形能力が完全に失われることとなる。すなわち、鉄骨梁が局部座屈や破断を生じることなく塑性変形能力を十分に発揮する場合の上記変形角θ３に比べると、塑性変形能力が大きく低下する。 However, as the end of the steel beam in the axial direction receives a bending moment, the deformation angle θ increases, and after exceeding the total plastic proof stress Mp, the deformation angle θ increases, as shown by the x mark in Fig. 1. If the end in the axial direction of the material breaks at θ1, the plastic deformation ability of the steel beam will be completely lost at this point. That is, compared to the deformation angle θ3 when the steel beam fully exhibits its plastic deformation ability without causing local buckling or fracture, the plastic deformation ability is greatly reduced.

鉄骨梁が地震力等の繰返し荷重を受けると、材軸方向の先端にひずみが集中して、この材軸方向の先端の破断が発生することが多い。これを防ぐためには、鉄骨梁の材軸方向の先端のひずみの集中を緩和することが重要である。 When a steel beam is subjected to repeated loads such as earthquake forces, strain concentrates at the tip in the axial direction of the beam, often causing fracture at the tip in the axial direction. In order to prevent this, it is important to alleviate the concentration of strain at the tip of the steel beam in the axial direction.

また、鉄骨梁の材軸方向の先端が破断しない場合であっても、ウェブの肉厚が小さい場合等には、鉄骨梁の材軸方向の端部で局部座屈が発生して、図１中に破線で示すように、鉄骨梁の耐力Ｍが急激に低下することがある。鉄骨梁が地震力等の繰返し荷重に対して十分な耐力を保持しながら、鉄骨梁に入力するエネルギーを吸収するためには、鉄骨梁の材軸方向の先端の破断だけでなく、材軸方向の端部の局部座屈も抑える必要がある。 In addition, even if the tip of the steel beam in the axial direction does not break, if the web thickness is small, local buckling may occur at the end of the steel beam in the axial direction, as shown in Figure 1. As shown by the broken line inside, the yield strength M of the steel beam may drop suddenly. In order for a steel beam to absorb the energy input to the steel beam while maintaining sufficient strength against repeated loads such as earthquake forces, it is necessary not only to break the tip of the steel beam in the axial direction. It is also necessary to suppress local buckling at the edges.

ここで、非特許文献１に開示されるように、鉄骨梁の材軸方向の端部に貫通孔を設けることによって、鉄骨梁の塑性変形能力の向上を図ろうとすると、図１に点線で示すように、貫通孔の位置の断面欠損に起因して、鉄骨梁の最大耐力が低下する。この耐力低下に対しては、上述のとおり、図１６や図１７に示すような方法で貫通孔の周囲を補強することにより、鉄骨梁の耐力を改善することが考えられる。 Here, as disclosed in Non-Patent Document 1, if an attempt is made to improve the plastic deformation ability of a steel beam by providing a through hole at the end of the steel beam in the axial direction, as shown by the dotted line in FIG. As such, the maximum yield strength of the steel beam decreases due to the cross-sectional defect at the location of the through hole. In order to deal with this decrease in strength, as described above, it is possible to improve the strength of the steel beam by reinforcing the periphery of the through hole using the method shown in FIGS. 16 and 17.

しかし、図１６や図１７に示すようなリングやスリーブ管による補強では、鉄骨梁が地震力等の短期荷重が作用して、材軸方向端部が曲げモーメントを受けるとき、この材軸方向の端部のフランジに発生する局部座屈を抑える効果が得られない。また、リングやスリーブ管は、貫通孔の径や形状に合わせて加工して製作する必要があるため、鋳鋼製のものが用いられることが多く、これらの部品のコストが高い問題もある。 However, when reinforcing with rings or sleeve tubes as shown in Figures 16 and 17, when a short-term load such as an earthquake force acts on a steel beam and the axial end of the material receives a bending moment, the axial It is not effective to suppress local buckling that occurs in the end flange. Furthermore, since the rings and sleeve tubes need to be processed and manufactured to match the diameter and shape of the through hole, they are often made of cast steel, and there is also the problem that the cost of these parts is high.

また、図１６や図１７に示すような方法により貫通孔の周囲を補強して、貫通孔の変形を拘束すると、貫通孔が設けられていない鉄骨梁と同等の塑性変形能力を確保することはできるが、貫通孔が設けられていない鉄骨梁以上に変形能力が向上することは期待できない。これは、リングやスリーブ管等の補強部材とウェブが溶接接合されて、貫通孔の周囲のウェブが拘束され、変形が妨げられるためである。また、リングやスリーブ管とウェブとの溶接は、肉厚が小さく変形が生じやすいウェブに設けられる貫通孔の周囲で行われるため、鉄骨梁や貫通孔が溶接変形を起こさないよう、溶接に高い技量が要求される問題もある。 Furthermore, if the periphery of the through hole is reinforced using the method shown in Figures 16 and 17 to restrain the deformation of the through hole, it is not possible to secure the same plastic deformation ability as a steel beam without through holes. However, it cannot be expected that the deformability will be any better than that of steel beams without through holes. This is because the web is welded to a reinforcing member such as a ring or sleeve pipe, and the web around the through hole is restrained and deformation is prevented. In addition, welding between the ring or sleeve pipe and the web is performed around the through-hole provided in the web, which has a small wall thickness and is prone to deformation. There are also problems that require skill.

また、非特許文献１では、サイズＨ-５００×２００×１０×１６のＨ形鋼からなる鉄骨梁の材軸方向の端部が曲げモーメントを受ける場合の挙動を、弾塑性有限要素解析で計算した結果が示されている、しかし、このようなウェブの幅厚比が小さい鉄骨梁ではそもそも座屈が生じにくく、ウェブの肉厚が小さい鉄骨梁に比べると塑性変形能力が高いことが知られている。近年では、建築物の高層化に伴い、鋼材重量の低減を図るべく、ウェブの肉厚が小さい鉄骨梁が採用される例が増加していることに鑑みれば、非特許文献１のように鉄骨梁の材軸方向の端部に貫通孔を設けるだけでは、鉄骨梁の塑性変形能力は必ずしも改善されないため、十分な塑性変形能力を得るには、材軸方向の端部の局部座屈も抑える必要がある。 In addition, in Non-Patent Document 1, the behavior of a steel beam made of H-beams of size H-500 x 200 x 10 x 16 when the end in the axial direction receives a bending moment is calculated using elastic-plastic finite element analysis. However, it is known that steel beams with a small web width-to-thickness ratio are less prone to buckling and have a higher plastic deformation capacity than steel beams with a smaller web thickness. ing. In recent years, as buildings have become taller, steel beams with smaller web thicknesses have been increasingly adopted in order to reduce the weight of steel materials. Merely providing through holes at the ends of the beam in the axial direction does not necessarily improve the plastic deformation ability of steel beams, so in order to obtain sufficient plastic deformation ability, local buckling at the ends in the axial direction must also be suppressed. There is a need.

また、非特許文献１には、梁せい５００ｍｍの鉄骨梁に直径３６０ｍｍの貫通孔が設けられている例では、貫通孔の近傍のフランジが局部座屈してしまい、鉄骨梁の塑性変形能力が向上していないことが示されている。このため、非特許文献１では、鉄骨梁の材軸方向の端部に貫通孔を形成する際に、小さな貫通穴を多数設ける方法を提案している。しかし、このような方法では、多数の貫通孔を形成するために工数が増加する問題がある。 Furthermore, in Non-Patent Document 1, in an example in which a through hole with a diameter of 360 mm is provided in a steel beam with a beam width of 500 mm, the flange near the through hole locally buckles, and the plastic deformation ability of the steel beam improves. It has been shown that they have not. For this reason, Non-Patent Document 1 proposes a method of providing a large number of small through holes when forming the through holes at the ends of the steel beam in the axial direction. However, such a method has a problem in that the number of man-hours increases due to the formation of a large number of through holes.

本発明は、上記のような事情に鑑みてなされたものであり、単純な構造により、地震力等の短期荷重作用時に材軸方向の端部の塑性変形能力を改善することのできる鉄骨梁、柱梁接合構造およびこれを有する構造物を提供することを目的とする。 The present invention has been made in view of the above circumstances, and provides a steel beam with a simple structure that can improve the plastic deformation ability of the ends in the axial direction when a short-term load such as an earthquake force is applied. The object of the present invention is to provide a column-beam joint structure and a structure having the same.

上記課題を解決するため、本発明は以下の特徴を有する。 In order to solve the above problems, the present invention has the following features.

［１］ 上フランジと、下フランジと、前記上フランジと前記下フランジとを連結するウェブとを有する鉄骨梁であって、該鉄骨梁の材軸方向の所定位置において、前記上フランジと前記下フランジの間を連結する主スチフナが設けられるとともに、前記ウェブには前記主スチフナと梁幅方向に重なるように貫通孔が形成されていることを特徴とする鉄骨梁。 [1] A steel beam having an upper flange, a lower flange, and a web connecting the upper flange and the lower flange, wherein the upper flange and the lower flange are connected at a predetermined position in the axial direction of the steel beam. A steel beam characterized in that a main stiffener is provided to connect flanges, and a through hole is formed in the web so as to overlap with the main stiffener in the beam width direction.

ここで、「主スチフナと梁幅方向に重なるように貫通孔が形成されている」とは、梁幅方向に見たときに貫通孔の少なくとも一部が主スチフナと重なることを意味する。 Here, "the through hole is formed so as to overlap the main stiffener in the beam width direction" means that at least a portion of the through hole overlaps with the main stiffener when viewed in the beam width direction.

［２］ 前記所定位置は、前記材軸方向の端部であることを特徴とする［１］に記載の鉄骨梁。 [2] The steel beam according to [1], wherein the predetermined position is an end in the axial direction of the material.

ここで、材軸方向の「端部」とは、鉄骨梁の材軸方向の先端が柱に接続されてなる構造物に、地震力等の短期荷重が作用するときの塑性化領域を意味し、例えば、鉄骨梁の材軸方向の先端から材軸方向に梁せいの１．５倍までの領域を指す。 Here, the term "end" in the axial direction refers to the plasticized region when a short-term load such as an earthquake force is applied to a structure in which the axial tip of a steel beam is connected to a column. , for example, refers to the area from the tip of a steel beam in the axial direction to 1.5 times the beam depth in the axial direction.

［３］ 前記主スチフナは、前記ウェブに接合されていないことを特徴とする［１］または［２］に記載の鉄骨梁。 [3] The steel beam according to [1] or [2], wherein the main stiffener is not joined to the web.

［４］ 前記主スチフナは、前記上フランジと前記下フランジの梁幅方向の先端部に配設されていることを特徴とする［１］～［３］のいずれかに記載の鉄骨梁。 [4] The steel beam according to any one of [1] to [3], wherein the main stiffener is disposed at the ends of the upper flange and the lower flange in the beam width direction.

［５］ 前記主スチフナは平板状の形状を有し、前記材軸方向と交差する向きに配設されていることを特徴とする［１］～［４］のいずれかに記載の鉄骨梁。 [5] The steel beam according to any one of [1] to [4], wherein the main stiffener has a flat plate shape and is disposed in a direction intersecting the material axis direction.

［６］ 前記材軸方向の端部のうち、前記貫通孔が形成されていない位置において、前記上フランジと前記下フランジとの間が、副スチフナにより連結されていることを特徴とする［１］～［５］のいずれかに記載の鉄骨梁。 [6] The upper flange and the lower flange are connected by a sub-stiffener at a position where the through hole is not formed in the end portion in the axial direction of the material [1] The steel beam according to any one of ] to [5].

［７］ 前記副スチフナは、前記貫通孔と前記鉄骨梁の長さ方向の先端との間に設けられていることを特徴とする［６］に記載の鉄骨梁。 [7] The steel beam according to [6], wherein the sub-stiffener is provided between the through hole and a longitudinal end of the steel beam.

［８］ 前記副スチフナは、前記ウェブに接合されていないことを特徴とする［６７］または［７］に記載の鉄骨梁。 [8] The steel beam according to [67] or [7], wherein the secondary stiffener is not joined to the web.

［９］ ［１］～［８］のいずれかに記載の鉄骨梁の前記材軸方向の先端が柱に接続されてなることを特徴とする柱梁接合構造。 [9] A column-beam joint structure, characterized in that the tip of the steel beam according to any one of [1] to [8] in the direction of the material axis is connected to a column.

［１０］ ［９］に記載の柱梁接合構造を有することを特徴とする構造物。 [10] A structure characterized by having the column-beam joint structure according to [9].

本発明の鉄骨梁、柱梁接合構造およびこれを有する構造物によれば、地震力等の短期荷重作用時に、貫通孔の周囲のウェブが、鉄骨梁の材軸方向の先端よりも先行して変形し降伏することにより、鉄骨梁の材軸方向の先端でのひずみの集中が緩和され、鉄骨梁の塑性変形能力が向上する。 According to the steel beam, column-beam joint structure, and structure having the same of the present invention, when a short-term load such as an earthquake force is applied, the web around the through hole precedes the tip of the steel beam in the axial direction. By deforming and yielding, the concentration of strain at the tip of the steel beam in the axial direction is alleviated, and the plastic deformation ability of the steel beam is improved.

また、上フランジと下フランジの間が、貫通孔の少なくとも一部と梁幅方向に重なるように配設された主スチフナにより連結されているので、鉄骨梁のウェブの肉厚が小さくても、ウェブの局部座屈が抑えられ、鉄骨梁の塑性変形能力が向上する。 In addition, since the upper flange and lower flange are connected by the main stiffener arranged so as to overlap at least a portion of the through hole in the beam width direction, even if the web thickness of the steel beam is small, Local buckling of the web is suppressed and the plastic deformation ability of the steel beam is improved.

また、上フランジと下フランジの間が、貫通孔の少なくとも一部と梁幅方向に重なるように配設された主スチフナにより連結されて、上フランジと下フランジが補剛されるので、小さな貫通孔を多数設けるような複雑な構造ではなく、比較的大きな貫通孔を一つまたは少数のみ設ける簡単な構造としても、貫通孔の近傍の上フランジおよび下フランジの局部座屈が抑えられ、鉄骨梁の塑性変形能力が向上する。 In addition, the upper flange and lower flange are connected by a main stiffener arranged so as to overlap at least a part of the through hole in the beam width direction, and the upper flange and lower flange are stiffened. Rather than a complex structure with many holes, even a simple structure with only one or a small number of relatively large through holes can suppress local buckling of the upper and lower flanges near the through holes, and improve the structure of steel beams. plastic deformation ability is improved.

また、鉄骨梁のウェブに設ける貫通孔の径を変更することにより、鉄骨梁の全塑性耐力を簡単に調整できる。 Further, by changing the diameter of the through hole provided in the web of the steel beam, the total plastic strength of the steel beam can be easily adjusted.

また、主スチフナおよび副スチフナは、上フランジと下フランジの間を連結するように取り付けられているので、これら主スチフナおよび副スチフナの形状を、貫通孔の形状に影響されることなく決定できる。 Moreover, since the main stiffener and the sub stiffener are attached to connect the upper flange and the lower flange, the shapes of the main stiffener and the sub stiffener can be determined without being influenced by the shape of the through hole.

本発明の鉄骨梁および従来の鉄骨梁における荷重－変形関係を模式的に示すグラフである。1 is a graph schematically showing a load-deformation relationship in a steel beam of the present invention and a conventional steel beam. 本発明の一実施形態の鉄骨梁および柱梁接合構造を示す図であり、（ａ）は側面図、（ｂ）は断面図である。BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the steel beam and column-beam joint structure of one Embodiment of this invention, (a) is a side view, (b) is a sectional view. 本発明の鉄骨梁の材軸方向の端部に曲げモーメントおよびせん断力が作用するときの変形状況を模式的に示す側面図である。FIG. 2 is a side view schematically showing a deformation state when a bending moment and a shear force are applied to the end portion of the steel beam of the present invention in the material axis direction. 本発明の他の実施形態の鉄骨梁および柱梁接合構造を示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the steel beam and column-beam joint structure of other embodiments of this invention, (a) is a side view, (b) is a sectional view. 本発明のさらに他の実施形態の鉄骨梁および柱梁接合構造を示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the steel beam and column-beam joint structure of further another embodiment of this invention, (a) is a side view, (b) is a sectional view. 本発明のさらに他の実施形態の鉄骨梁および柱梁接合構造を示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the steel beam and column-beam joint structure of further another embodiment of this invention, (a) is a side view, (b) is a sectional view. 本発明のさらに他の実施形態の鉄骨梁および柱梁接合構造を示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the steel beam and column-beam joint structure of further another embodiment of this invention, (a) is a side view, (b) is a sectional view. 本発明のさらに他の実施形態の鉄骨梁および柱梁接合構造を示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the steel beam and column-beam joint structure of further another embodiment of this invention, (a) is a side view, (b) is a sectional view. 本発明の鉄骨梁が荷重を受けるときの変形を数値解析により計算するための解析モデルを示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the analytical model for calculating the deformation|transformation when the steel beam of this invention receives a load by numerical analysis, (a) is a side view, (b) is a sectional view. 従来の鉄骨梁が荷重を受けるときの変形を数値解析により計算するための解析モデルを示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the analytical model for calculating the deformation|transformation when a conventional steel beam receives a load by numerical analysis, (a) is a side view, (b) is a cross-sectional view. 従来の鉄骨梁が荷重を受けるときの変形を数値解析により計算するための解析モデルを示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows the analytical model for calculating the deformation|transformation when a conventional steel beam receives a load by numerical analysis, (a) is a side view, (b) is a cross-sectional view. 本発明と従来の鉄骨梁における荷重－変形関係を数値解析により計算した結果を比較して示すグラフである。1 is a graph showing a comparison of the results of numerical analysis of the load-deformation relationship between the present invention and a conventional steel beam; 本発明の鉄骨梁に発生するひずみ分布の数値解析結果を示すコンター図であり、（ａ）は側面図、（ｂ）は上面図である。FIG. 2 is a contour diagram showing numerical analysis results of strain distribution occurring in a steel beam according to the present invention, in which (a) is a side view and (b) is a top view. 従来の鉄骨梁に発生するひずみ分布の数値解析結果を示すコンター図であり、（ａ）は側面図、（ｂ）は上面図である。It is a contour diagram which shows the numerical analysis result of the strain distribution which generate|occur|produces in the conventional steel beam, (a) is a side view, (b) is a top view. 従来の鉄骨梁に発生するひずみ分布の数値解析結果を示すコンター図であり、（ａ）は側面図、（ｂ）は上面図である。It is a contour diagram which shows the numerical analysis result of the strain distribution which generate|occur|produces in the conventional steel beam, (a) is a side view, (b) is a top view. 従来の鉄骨梁の一例を示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows an example of a conventional steel beam, (a) is a side view, (b) is a sectional view. 従来の鉄骨梁の他の一例を示す図であり、（ａ）は側面図、（ｂ）は断面図である。It is a figure which shows another example of the conventional steel beam, (a) is a side view, (b) is a sectional view.

以下、図面を参照して、本発明の鉄骨梁、柱梁接合構造およびこれを有する構造物の実施形態を詳細に説明する。 EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, embodiments of the steel beam, column-beam joint structure of the present invention, and a structure having the same will be described in detail.

本実施の形態の鉄骨梁は、鉄骨造の建築物（構造物）（図示せず）に設けられるものである。図２（ａ）および図２（ｂ）はそれぞれ、本実施の形態の鉄骨梁１の側面図、および、後述する貫通孔１３ｈの位置で材軸方向に直交する面で切断した断面図である。この鉄骨梁１では、上フランジ１１と、下フランジ１２と、これら上フランジ１１と下フランジ１２とを連結するウェブ１３とを有するＨ形鋼の材軸方向の端部、すなわち建築物の柱２に接続される部分の近傍において、Ｈ形鋼の上フランジ１１と下フランジ１２の間を連結する主スチフナ１４が設けられている。 The steel beam of this embodiment is provided in a steel frame building (structure) (not shown). 2(a) and 2(b) are a side view of the steel beam 1 according to the present embodiment, and a cross-sectional view taken along a plane perpendicular to the material axis direction at the position of a through hole 13h, which will be described later. . In this steel beam 1, an end in the axial direction of an H-shaped steel having an upper flange 11, a lower flange 12, and a web 13 connecting the upper flange 11 and the lower flange 12, that is, a column 2 of a building A main stiffener 14 that connects the upper flange 11 and the lower flange 12 of the H-section steel is provided near the portion connected to the H-section steel.

さらに、Ｈ形鋼のウェブ１３には、主スチフナ１４と梁幅方向に重なるように貫通孔１３ｈが形成されている。つまり、上フランジ１１と下フランジ１２の間を連結する主スチフナ１４は、貫通孔１３ｈの少なくとも一部と梁幅方向に重なるように配設されている。図２（ｂ）に示すように、主スチフナ１４は、平板状の形状を有し、鉄骨梁１の材軸方向と交差する向き、すなわちウェブ１３、上フランジ１１および下フランジ１２の各々に対して垂直に配設されている。 Further, a through hole 13h is formed in the web 13 of the H-shaped steel so as to overlap the main stiffener 14 in the beam width direction. That is, the main stiffener 14 that connects the upper flange 11 and the lower flange 12 is arranged so as to overlap at least a portion of the through hole 13h in the beam width direction. As shown in FIG. 2(b), the main stiffener 14 has a flat plate shape, and is directed toward each of the web 13, the upper flange 11, and the lower flange 12 in a direction intersecting the axial direction of the steel beam 1. vertically arranged.

また、図２に示すように、鉄骨梁１の材軸方向の端部のうち、貫通孔１３ｈが形成されていない位置では、上フランジ１１と下フランジ１２との間が、鉄骨梁１のウェブ１３の両側に配設された副スチフナ１６により連結されている。具体的には、鉄骨梁１の材軸方向の先端と貫通孔１３ｈとの間の一箇所に、副スチフナ１６が設けられている。図２（ａ）に示すように、副スチフナ１６および主スチフナ１４は、鉄骨梁１の材軸方向に均等な間隔で配設されている。副スチフナ１６は、主スチフナ１４と同様に、平板状の形状を有し、鉄骨梁１の材軸方向と交差する向き、すなわちウェブ１３、上フランジ１１および下フランジ１２の各々に対して垂直に配設されている。 Further, as shown in FIG. 2, at a position where the through hole 13h is not formed at the end of the steel beam 1 in the material axis direction, the web of the steel beam 1 is located between the upper flange 11 and the lower flange 12. 13 are connected by sub-stiffeners 16 disposed on both sides. Specifically, the sub-stiffener 16 is provided at one location between the tip of the steel beam 1 in the material axis direction and the through hole 13h. As shown in FIG. 2(a), the sub-stiffeners 16 and the main stiffeners 14 are arranged at equal intervals in the axial direction of the steel beam 1. Like the main stiffener 14, the sub stiffener 16 has a flat plate shape, and is oriented in a direction that intersects with the axial direction of the steel beam 1, that is, perpendicular to each of the web 13, the upper flange 11, and the lower flange 12. It is arranged.

主スチフナ１４および副スチフナ１６は、上フランジ１１と下フランジ１２の梁幅方向の先端に接合されて、上フランジ１１および下フランジ１２の面外変形を拘束している。主スチフナ１４および副スチフナ１６は、ウェブ１３との間に隙間が形成されるように配設されており、ウェブ１３には接合されていない。 The main stiffener 14 and the sub stiffener 16 are joined to the ends of the upper flange 11 and the lower flange 12 in the beam width direction, and restrain out-of-plane deformation of the upper flange 11 and the lower flange 12. The main stiffener 14 and the sub-stiffener 16 are arranged so that a gap is formed between them and the web 13, and are not joined to the web 13.

そして、鉄骨梁１の材軸方向の先端が柱２に接続されて、柱梁接合構造３が構成される。 Then, the tip of the steel beam 1 in the material axis direction is connected to the column 2 to form a column-beam joint structure 3.

本実施の形態の鉄骨梁１の材軸方向の端部に曲げモーメントが作用するときの変形状態を、図３に模式的に示す。 FIG. 3 schematically shows a deformed state when a bending moment is applied to the end portion of the steel beam 1 in the axial direction of the present embodiment.

上述のとおり、主スチフナ１４および副スチフナ１６は、ウェブ１３には接合されていないため、貫通孔１３ｈの周囲のウェブ１３の変形が拘束されない。したがって、図３に示すように、貫通孔１３ｈの周囲のウェブ１３が、鉄骨梁１の材軸方向の先端よりも先行して変形し降伏することにより、鉄骨梁１の材軸方向の先端でのひずみの集中が緩和され鉄骨梁１の塑性変形能力が向上する。 As described above, since the main stiffener 14 and the sub-stiffener 16 are not joined to the web 13, the deformation of the web 13 around the through hole 13h is not restrained. Therefore, as shown in FIG. 3, the web 13 around the through hole 13h deforms and yields before the tip of the steel beam 1 in the axial direction, so that the tip of the steel beam 1 in the axial direction The concentration of strain is alleviated, and the plastic deformation ability of the steel beam 1 is improved.

また、貫通孔１３ｈの断面欠損やウェブ１３の肉厚が小さいことに起因する、貫通孔１３ｈの近傍の上フランジ１１、下フランジ１２およびウェブ１３の局部座屈が、主スチフナ１４および副スチフナ１６によって上フランジ１１と下フランジ１２の間が連結されることによって抑えられる。 In addition, local buckling of the upper flange 11, lower flange 12, and web 13 in the vicinity of the through hole 13h due to the cross-sectional defect of the through hole 13h or the small wall thickness of the web 13 may occur in the main stiffener 14 and the secondary stiffener 16. This is suppressed by connecting the upper flange 11 and the lower flange 12.

この結果、本実施形態の鉄骨梁は、図１中に一点鎖線で示すように、全塑性耐力Ｍｐに到達した後、貫通孔が設けられていない従来の鉄骨梁よりも緩やかな勾配で、耐力Ｍが上昇し、その後低下していくこととなる。そして、本実施形態の鉄骨梁では、耐力Ｍが全塑性耐力Ｍｐ以上を維持できる限界の変形角がθ５となり、貫通孔が設けられていない従来の鉄骨梁や、貫通孔は設けられるが主スチフナや副スチフナが設けられていない従来の鉄骨梁に比べて、塑性変形能力が向上する。 As a result, as shown by the dashed line in FIG. 1, the steel beam of this embodiment, after reaching the total plastic proof stress Mp, has a gentler slope than the conventional steel beam without through-holes. M increases and then decreases. In the steel beam of this embodiment, the limit deformation angle at which the proof stress M can maintain the total plastic proof stress Mp or more is θ5, and the conventional steel beam with no through holes and the main stiffener with through holes are The plastic deformation capacity is improved compared to conventional steel beams that are not provided with stiffeners or secondary stiffeners.

図４～８に、本発明の鉄骨梁および柱梁接合構造の他の実施の形態を示す。 4 to 8 show other embodiments of the steel beam and column-beam joint structure of the present invention.

図４（ａ）および図４（ｂ）に示す鉄骨梁１Ａおよび柱梁接合構造３Ａでは、図２（ａ）および図２（ｂ）に示す鉄骨梁１および柱梁接合構造３とは異なり、主スチフナ１４Ａは、鉄骨梁１のウェブ１３に平行な向きに配設され、また副スチフナ１６が配設されていない。その他は、図２（ａ）および図２（ｂ）に示す鉄骨梁１および柱梁接合構造３と同様に構成されている。 The steel beam 1A and beam-column joint structure 3A shown in FIGS. 4(a) and 4(b) differ from the steel beam 1 and beam-column joint structure 3 shown in FIGS. 2(a) and 2(b), The main stiffener 14A is arranged parallel to the web 13 of the steel beam 1, and the sub stiffener 16 is not arranged. The other structures are the same as the steel beam 1 and beam-column joint structure 3 shown in FIGS. 2(a) and 2(b).

このように、平板状の形状を有する主スチフナ１４Ａを鉄骨梁１のウェブ１３に平行な向きに配設することにより、面外変形が大きく発生しやすい上フランジ１１や下フランジ１２の梁幅方向の先端において、これら上フランジ１１や下フランジ１２の面外変形がより効果的に抑えられ、上フランジ１１や下フランジ１２の局部座屈を防止できる。 In this way, by arranging the main stiffener 14A having a flat plate shape in a direction parallel to the web 13 of the steel beam 1, the upper flange 11 and the lower flange 12, which are likely to undergo large out-of-plane deformation, are prevented in the beam width direction. At the tips of the upper flange 11 and the lower flange 12, out-of-plane deformation can be more effectively suppressed, and local buckling of the upper flange 11 and the lower flange 12 can be prevented.

図５（ａ）および図５（ｂ）に示す鉄骨梁１Ｂおよび柱梁接合構造３Ｂでは、図２（ａ）および図２（ｂ）に示す鉄骨梁１および柱梁接合構造３とは異なり、平板状の形状を有する主スチフナ１４Ｂが貫通孔１３ｈの全体を覆うようにして、貫通孔１３ｈの周囲のウェブ１３の両側に重ねて配設され、上フランジ１１と下フランジ１２に接合されている。主スチフナ１４Ｂは、ウェブ１３に重ねて配設されているが、ウェブ１３には接合されていないため、ウェブ１３の面該変形を拘束するが、ウェブ１３のせん断変形を拘束しない。 In the steel beam 1B and beam-column joint structure 3B shown in FIGS. 5(a) and 5(b), unlike the steel beam 1 and beam-column joint structure 3 shown in FIGS. 2(a) and 2(b), A main stiffener 14B having a flat plate shape is disposed overlappingly on both sides of the web 13 around the through hole 13h so as to cover the entire through hole 13h, and is joined to the upper flange 11 and the lower flange 12. . The main stiffener 14B is disposed overlapping the web 13, but is not joined to the web 13, so it restrains the surface deformation of the web 13, but does not restrain the shear deformation of the web 13.

このように、平板状の形状を有する主スチフナ１４Ｂを貫通孔１３ｈの全体を覆うようにして貫通孔１３ｈの周囲のウェブ１３の両側に重ねて配設することで、ウェブ１３の面外変形が抑えられ、鉄骨梁１のねじり変形が抑えられる。 In this way, by disposing the main stiffener 14B having a flat plate shape on both sides of the web 13 around the through hole 13h so as to cover the entire through hole 13h, out-of-plane deformation of the web 13 can be prevented. This suppresses torsional deformation of the steel beam 1.

図６（ａ）および図６（ｂ）に示す鉄骨梁１Ｃおよび柱梁接合構造３Ｃは、図５（ａ）および図５（ｂ）に示す鉄骨梁１Ｂおよび柱梁接合構造３Ｂの平板状の主スチフナ１４Ｂを、形鋼などの成形品により構成された主スチフナ１４Ｃで置き換えたものである。このように、必要に応じて主スチフナの形状を変えてもよい。 The steel beam 1C and column-beam joint structure 3C shown in FIGS. 6(a) and 6(b) are similar to the flat plate-shaped steel beam 1B and column-beam joint structure 3B shown in FIGS. 5(a) and 5(b). The main stiffener 14B is replaced with a main stiffener 14C made of a molded product such as a section steel. In this way, the shape of the main stiffener may be changed as necessary.

図７（ａ）および図７（ｂ）、ならびに図８（ａ）および図８（ｂ）に示す鉄骨梁１Ｄ、１Ｅおよび柱梁接合構造３Ｄ、３Ｅでは、図２（ａ）および図２（ｂ）に示す鉄骨梁１および柱梁接合構造３とは異なり、貫通孔１３ｈＤ、１３ｈＥの形状が円形ではなく楕円形または多角形に形成されている。このように、必要に応じて貫通孔の形状を変えても良い。 In the steel beams 1D, 1E and column-beam joint structures 3D, 3E shown in FIGS. 7(a) and 7(b) and FIGS. 8(a) and 8(b), FIGS. 2(a) and 2( Unlike the steel beam 1 and beam-column joint structure 3 shown in b), the shapes of the through holes 13hD and 13hE are not circular but elliptical or polygonal. In this way, the shape of the through hole may be changed as necessary.

なお、本発明の鉄骨梁においては、貫通孔の大きさを梁せいの半分以下とすることが好ましく、その範囲内で貫通孔の大きさを変更することにより、鉄骨梁の全塑性耐力を調整することができる。 In addition, in the steel beam of the present invention, it is preferable that the size of the through hole be less than half of the beam thickness, and by changing the size of the through hole within this range, the total plastic strength of the steel beam can be adjusted. can do.

貫通孔、主スチフナおよび副スチフナが設けられている本発明の鉄骨梁（本発明例）と、貫通孔、主スチフナ、副スチフナのいずれも設けられていない従来の鉄骨梁（従来例１）と、貫通孔が設けられ主スチフナ、副スチフナが設けられていない従来の鉄骨梁（従来例２）を対象として、有限要素法による数値解析を行い、耐力および変形能力を確認した。 A steel beam of the present invention in which a through hole, a main stiffener, and a sub-stiffener are provided (example of the present invention), and a conventional steel beam in which neither a through hole, a main stiffener, nor a sub-stiffener are provided (conventional example 1). A numerical analysis using the finite element method was conducted on a conventional steel beam (conventional example 2) with through holes and no main stiffeners or sub stiffeners, and the strength and deformation capacity were confirmed.

本数値解析における解析モデルを、図９～図１１に示す。図９に示すように、本発明例の鉄骨梁１Ｆの解析モデルとして、Ｈ－１０００（Ｈ）×３００（Ｂ）×１２×２５、全長Ｌ＝２００００ｍｍのＨ形鋼のウェブ１３に、直径５００ｍｍの貫通孔１３ｈが形成され、Ｈ形鋼の上フランジ１１と下フランジ１２の間が、材軸方向と直交する向きに配設された主スチフナ１４および副スチフナ１６、１７により連結されているものを設定した。主スチフナ１４および副スチフナ１６、１７のサイズは、高さ９５０ｍｍ、幅１４４ｍｍ、厚さ１２ｍｍとした。 The analytical models used in this numerical analysis are shown in FIGS. 9 to 11. As shown in FIG. 9, as an analysis model of the steel beam 1F of the example of the present invention, a web 13 of H-beam steel with a size of H-1000 (H) x 300 (B) x 12 x 25, total length L = 20,000 mm, and a diameter of 500 mm. A through hole 13h is formed, and the upper flange 11 and lower flange 12 of the H-section steel are connected by a main stiffener 14 and sub stiffeners 16 and 17 arranged perpendicular to the material axis direction. It was set. The main stiffener 14 and the sub stiffeners 16 and 17 had a height of 950 mm, a width of 144 mm, and a thickness of 12 mm.

貫通孔１３ｈの中心位置は、鉄骨梁１Ｆの材軸方向の先端から６００ｍｍの位置とした。また、鉄骨梁１Ｆのウェブ１３の両側の各々に、材軸方向の先端から順に、副スチフナ１６が一箇所、主スチフナ１４が一箇所、副スチフナ１７が二箇所、材軸方向に均等な間隔Ｌ１＝３００ｍｍで配設されているものとした。また、主スチフナ１４および副スチフナ１６、１７は、鉄骨梁１Ｆの上フランジ１１の下面および下フランジ１２の上面に接合される一方、ウェブ１３には接合されていないものとした。各溶接部はノンスカラップ型とした。 The center position of the through hole 13h was set at a position 600 mm from the tip of the steel beam 1F in the material axis direction. Furthermore, on each of both sides of the web 13 of the steel beam 1F, in order from the tip in the direction of the material axis, one sub-stiffener 16, one main stiffener 14, and two sub-stiffeners 17 are placed at equal intervals in the direction of the material axis. It is assumed that the distance L1 is 300 mm. Further, the main stiffener 14 and the sub-stiffeners 16 and 17 were connected to the lower surface of the upper flange 11 and the upper surface of the lower flange 12 of the steel beam 1F, but were not connected to the web 13. Each weld was of a non-scalloped type.

そして、本発明例の鉄骨梁１Ｆが逆対称曲げを受けることを想定し、対称性を考慮して、鉄骨梁１Ｆの全長Ｌの半分Ｌ／２までを解析モデル化した。 Then, assuming that the steel beam 1F of the example of the present invention is subjected to antisymmetrical bending, up to half L/2 of the total length L of the steel beam 1F was made into an analytical model in consideration of symmetry.

Ｈ形鋼の力学特性としては、ＪＩＳ Ｇ３１３６（建築構造用圧延鋼材）のＳＮ４９０Ｂ相当（引張強度：５５７Ｎ／ｍｍ２、降伏強度：３８５Ｎ／ｍｍ２、ヤング係数：２０５０００）を想定した応力－歪関係を用いた。また、主スチフナ１４および副スチフナ１６、１７の力学特性としては、ＪＩＳ Ｇ３１０１（一般構造用圧延鋼材）のＳＳ４００相当（引張強度：４２５Ｎ／ｍｍ２、降伏強度：２９５Ｎ／ｍｍ２、ヤング係数：２０５０００）を想定した応力－歪関係を用いた。 The mechanical properties of H-section steel are based on the stress-strain relationship assuming JIS G3136 (rolled steel for building structures) equivalent to SN490B (tensile strength: 557 N/mm 2 , yield strength: 385 N/mm 2 , Young's modulus: 205000). was used. In addition, the mechanical properties of the main stiffener 14 and the sub-stiffeners 16 and 17 are equivalent to SS400 of JIS G3101 (rolled steel for general structural use) (tensile strength: 425 N/mm 2 , yield strength: 295 N/mm 2 , Young's modulus: 205000 ) was used.

また、図１０に示すように、従来例１として、本発明例の貫通孔１３ｈ、主スチフナ１４、副スチフナ１６、１７のいずれも設けられておらず、その他は本発明例と同じとした解析モデルを設定した。さらに、図１１に示すように、従来例２として、本発明例の主スチフナ１４および副スチフナ１６、１７が設けられておらず、貫通孔１３ｈは本発明例と同様に形成され、その他も本発明例と同じとした解析モデルを設定した。 In addition, as shown in FIG. 10, as a conventional example 1, neither the through hole 13h, the main stiffener 14, nor the sub-stiffeners 16 and 17 of the example of the present invention are provided, and the other aspects are the same as the example of the present invention. The model was set. Furthermore, as shown in FIG. 11, as a conventional example 2, the main stiffener 14 and the sub-stiffeners 16, 17 of the example of the present invention are not provided, the through hole 13h is formed in the same way as the example of the present invention, and the others are also the same as the example of the present invention. An analysis model was set that was the same as the invention example.

これらの解析モデルについて、鉄骨梁１Ｆの材軸方向の先端（本発明例および比較例２においては、貫通孔１３ｈが形成されている側の先端）を完全固定とし、全長Ｌの半分Ｌ／２の位置を載荷点とした。この載荷点に、図９～図１１に示すように、梁せい方向上向きの荷重Ｐを作用させ、この荷重Ｐを漸増させていき、弾塑性有限要素法解析により、解析モデルの各部位の変形量および相当塑性ひずみを計算した。 For these analytical models, the tip of the steel beam 1F in the material axis direction (in the present invention example and comparative example 2, the tip on the side where the through hole 13h is formed) is completely fixed, and The position was taken as the loading point. As shown in Figs. 9 to 11, a load P is applied upward in the beam direction to this loading point, and this load P is gradually increased, and elastic-plastic finite element analysis is performed to determine the deformation of each part of the analytical model. The amount and equivalent plastic strain were calculated.

本発明例、従来例１、従来例２の各々について上記数値解析を行った結果得られた、鉄骨梁の材軸方向の先端にかかる曲げモーメントＭと、鉄骨梁の変形角θとの関係を、図１２に示す。ここで、鉄骨梁の材軸方向の先端にかかる曲げモーメントＭは、載荷点に作用させる荷重Ｐと、載荷点から固定端までの距離Ｌ／２の積により算出した。鉄骨梁の変形角θは、鉄骨梁の載荷点の鉛直変位δを、上記距離Ｌ／２で除すことによって算出した。図１２のグラフでは、縦軸は、上記曲げモーメントＭを、従来例１の全塑性モーメントＭｐで除した値Ｍ／Ｍｐである。また、横軸は、上記変形角θを、従来例１の全塑性モーメントＭｐ時の変形角θｐで除した無次元化変形角θ／θｐである。 The relationship between the bending moment M applied to the tip of the steel beam in the axial direction and the deformation angle θ of the steel beam, which was obtained as a result of the above numerical analysis for each of the present invention example, conventional example 1, and conventional example 2, is , shown in FIG. Here, the bending moment M applied to the tip of the steel beam in the axial direction was calculated by the product of the load P applied to the loading point and the distance L/2 from the loading point to the fixed end. The deformation angle θ of the steel beam was calculated by dividing the vertical displacement δ of the loading point of the steel beam by the distance L/2. In the graph of FIG. 12, the vertical axis is the value M/Mp obtained by dividing the bending moment M by the total plastic moment Mp of Conventional Example 1. Moreover, the horizontal axis is the dimensionless deformation angle θ/θp obtained by dividing the deformation angle θ by the deformation angle θp at the total plastic moment Mp of Conventional Example 1.

図１２に示すように、貫通孔が設けられ主スチフナおよび副スチフナが設けられていない従来例２では、貫通孔、主スチフナ、副スチフナのいずれも設けられていない従来例１に比べて、最大耐力発揮時、すなわち曲げモーメントＭが最大となるときの変形角θが大きくなっており、貫通孔が設けられることにより鉄骨梁の変形能力が向上していることがわかる。しかし、従来例２の最大耐力は、従来例１の最大耐力を下回っており、貫通孔が設けられている影響で最大耐力が低下してしまっていることがわかる。 As shown in FIG. 12, in conventional example 2 in which a through hole is provided and a main stiffener and a sub stiffener are not provided, the maximum It can be seen that the deformation angle θ is large when the yield strength is exerted, that is, when the bending moment M is maximum, and the deformation ability of the steel beam is improved by providing the through holes. However, the maximum yield strength of Conventional Example 2 is lower than the maximum yield strength of Conventional Example 1, and it can be seen that the maximum yield strength is lowered due to the influence of the provision of the through hole.

これに対し、貫通孔に加えて主スチフナおよび副スチフナが設けられている本発明例では、従来例１および従来例２に比べて、最大耐力発揮時の変形角θ、すなわち変形性能が大幅に向上している。また、本発明例の最大耐力は、従来例１および従来例２の最大耐力を上回っている。 On the other hand, in the example of the present invention in which a main stiffener and a sub-stiffener are provided in addition to the through hole, the deformation angle θ when the maximum yield strength is exerted, that is, the deformation performance, is significantly lower than in conventional examples 1 and 2. It's improving. Further, the maximum yield strength of the example of the present invention exceeds the maximum yield strength of Conventional Example 1 and Conventional Example 2.

図１３～図１５は、上記数値解析を行った結果得られた、無次元化変形角θ／θｐ＝５．０時点での鉄骨梁の各部位の相当塑性ひずみを、本発明例および従来例１、２の各々についてそれぞれ濃淡のコンターで示した図である。 13 to 15 show the equivalent plastic strain of each part of the steel beam at the nondimensional deformation angle θ/θp=5.0, obtained as a result of the above numerical analysis, for the present invention example and the conventional example. 1 and 2 are each shown as contours of shading.

従来例１では、図１３に示すように、相当塑性ひずみは、鉄骨梁の材軸方向の先端の近傍で集中的に発生しており、相当塑性ひずみが最大となる位置は、鉄骨梁の材軸方向の先端の上フランジである。 In Conventional Example 1, as shown in Fig. 13, the equivalent plastic strain occurs intensively near the tip of the steel beam in the axial direction, and the position where the equivalent plastic strain is maximum is at the tip of the steel beam. This is the upper flange of the axial tip.

また、従来例２では、図１４に示すように、相当塑性ひずみが最大となる位置は、鉄骨梁の貫通孔の近傍の上フランジとなっている。つまり、従来例２のように、貫通孔が設けられることにより、相当塑性ひずみが集中的に発生する位置が、鉄骨梁の材軸方向の先端から貫通孔の近傍に移動して、鉄骨梁が柱に接合される溶接部での破断を防ぐ効果が得られることがわかる。 Furthermore, in Conventional Example 2, as shown in FIG. 14, the position where the equivalent plastic strain is maximum is the upper flange near the through hole of the steel beam. In other words, as in Conventional Example 2, by providing a through hole, the position where equivalent plastic strain occurs intensively moves from the tip of the steel beam in the axial direction to the vicinity of the through hole, and the steel beam It can be seen that the effect of preventing breakage at the welded part connected to the column can be obtained.

さらに、本発明例では、図１５に示すように、相当塑性ひずみが最大となる位置は、鉄骨梁の貫通孔の上側のウェブとなっている。つまり、本発明例のように、貫通孔に加えて主スチフナおよび副スチフナが設けられることにより、相当塑性ひずみが集中的に発生する位置が、貫通孔の近傍の上フランジから貫通孔の上側のウェブに移動して、貫通孔の近傍のフランジの局部座屈を抑える効果がさらに得られることがわかる。フランジの局部座屈は、鉄骨梁の最大耐力を決定する主な要因であり、本発明例ではフランジの局部座屈が抑えられることで、鉄骨梁の塑性変形能力が大幅に向上することが確認された。 Furthermore, in the example of the present invention, as shown in FIG. 15, the position where the equivalent plastic strain is maximum is the web above the through-hole of the steel beam. In other words, by providing the main stiffener and the sub-stiffener in addition to the through-hole as in the example of the present invention, the position where equivalent plastic strain is concentrated is shifted from the upper flange near the through-hole to the upper side of the through-hole. It can be seen that by moving to the web, the effect of suppressing local buckling of the flange near the through hole can be further obtained. Local buckling of flanges is the main factor determining the maximum strength of steel beams, and in the example of the present invention, it was confirmed that by suppressing local buckling of flanges, the plastic deformation ability of steel beams was significantly improved. It was done.

１、１Ａ～１Ｆ 鉄骨梁
２ 柱
３、３Ａ～３Ｅ 柱梁接合構造
１１ 上フランジ
１２ 下フランジ
１３ ウェブ
１３ｈ、１３ｈＤ、１３ｈＥ 貫通孔
１４、１４Ａ～１４Ｃ、１４Ｆ 主スチフナ
１６、１７ 副スチフナ 1, 1A to 1F Steel beam 2 Column 3, 3A to 3E Column beam joint structure 11 Upper flange 12 Lower flange 13 Web 13h, 13hD, 13hE Through hole 14, 14A to 14C, 14F Main stiffener 16, 17 Secondary stiffener

Claims (9)

上フランジと、下フランジと、前記上フランジと前記下フランジとを連結するウェブとを有する鉄骨梁であって、
前記鉄骨梁の材軸方向の先端から材軸方向に梁せいの１．５倍までの領域内において、前記上フランジと前記下フランジの間を連結する主スチフナが設けられるとともに前記ウェブには貫通孔が形成され、梁幅方向に見たときに前記主スチフナの少なくとも一部が前記貫通孔と重なることを特徴とする鉄骨梁。 A steel beam having an upper flange, a lower flange, and a web connecting the upper flange and the lower flange,
A main stiffener connecting the upper flange and the lower flange is provided in an area extending from the tip of the steel beam in the axial direction to 1.5 times the beam width in the axial direction, and the web A steel beam characterized in that a through hole is formed in the beam, and at least a portion of the main stiffener overlaps the through hole when viewed in the width direction of the beam. 前記主スチフナは、前記ウェブに接合されていないことを特徴とする請求項１に記載の鉄骨梁。 The steel beam according to claim 1 , wherein the main stiffener is not joined to the web. 前記主スチフナは、前記上フランジと前記下フランジの梁幅方向の先端部に配設されていることを特徴とする請求項１または２のいずれかに記載の鉄骨梁。 3. The steel beam according to claim 1 , wherein the main stiffener is disposed at the ends of the upper flange and the lower flange in the beam width direction. 前記主スチフナは平板状の形状を有し、前記材軸方向と交差する向きに配設されていることを特徴とする請求項１～３のいずれかに記載の鉄骨梁。 The steel beam according to any one of claims 1 to 3, wherein the main stiffener has a flat plate shape and is arranged in a direction intersecting the direction of the material axis. 前記材軸方向の端部のうち、前記貫通孔が形成されていない位置において、前記上フランジと前記下フランジとの間が、副スチフナにより連結されていることを特徴とする請求
項１～４のいずれかに記載の鉄骨梁。 Claims 1 to 4 , wherein the upper flange and the lower flange are connected by a sub-stiffener at a position in the end portion in the material axis direction where the through hole is not formed. Steel beams listed in any of the above. 前記副スチフナは、前記貫通孔と前記鉄骨梁の長さ方向の先端との間に設けられていることを特徴とする請求項５に記載の鉄骨梁。 The steel beam according to claim 5 , wherein the secondary stiffener is provided between the through hole and a longitudinal end of the steel beam. 前記副スチフナは、前記ウェブに接合されていないことを特徴とする請求項５または６に記載の鉄骨梁。 The steel beam according to claim 5 or 6 , wherein the secondary stiffener is not joined to the web. 請求項１～７のいずれかに記載の鉄骨梁の前記材軸方向の先端が柱に接続されてなることを特徴とする柱梁接合構造。 A column-beam joint structure, characterized in that the tip of the steel beam according to any one of claims 1 to 7 in the direction of the material axis is connected to a column. 請求項８に記載の柱梁接合構造を有することを特徴とする構造物。 A structure comprising the column-beam joint structure according to claim 8 .
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014041631A1 (en) 2012-09-12 2014-03-20 中国電力株式会社 Structure for reinforcing web opening in steel frame
JP2015004254A (en) 2013-06-24 2015-01-08 株式会社ショーワ Structural material and manufacturing method of this structural material
JP2018172892A (en) 2017-03-31 2018-11-08 Ｊｆｅスチール株式会社 Reinforcing structure of beam and reinforcing method of beam

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014041631A1 (en) 2012-09-12 2014-03-20 中国電力株式会社 Structure for reinforcing web opening in steel frame
JP2015004254A (en) 2013-06-24 2015-01-08 株式会社ショーワ Structural material and manufacturing method of this structural material
JP2018172892A (en) 2017-03-31 2018-11-08 Ｊｆｅスチール株式会社 Reinforcing structure of beam and reinforcing method of beam

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