JP2003201737A - Joint structure - Google Patents

Abstract

(57) Abstract: A joint structure capable of greatly improving proof stress and fatigue performance by relieving stress concentration and welding heat residual stress at a toe of a plate-shaped member. A reinforcing rib (3) protruding in a T shape extending in the main stress direction of the structural member (1) is welded to a surface of the structural member (1).
The end of the reinforcing rib 3 in the main stress direction is bent along the surface of the structural member 1 in a direction away from the main stress direction. Thereby, the end portion 4 has low rigidity, and stress concentration is reduced. It is preferable that the end portion 4 of the plate-shaped member 3 is relaxed and bent in a curved shape, and it is preferable that the end portion 4 bend until it becomes perpendicular to the main stress direction. In the invention of claim 7, the same effect is obtained by bending the end of the anchor bolt in a direction away from the main stress direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonded structure in which various structural members are provided with plate members such as reinforcing ribs and anchor bolts.

[0002]

2. Description of the Related Art For example, a joining structure as shown in FIGS. 15 and 16 has been conventionally used for a joining portion between a steel structural pedestal structure and a foundation. In this conventional joint structure, a base plate 11 for bolt joint is welded to an end portion of the structural member 10 and a reinforcing rib 12 is reinforced between the structural member 10 and the base plate 11.
The reinforcing rib 12 is a plate-shaped member that extends in the principal stress direction of the structural member 10, and is provided so as to project in a T shape with respect to the surface of the structural member 10.

However, in the conventional joint structure as described above, when a bending moment acts on the structural member 10, a large out-of-plane bending stress concentration occurs in the structural member 10 near the toe of the reinforcing rib 12, resulting in structural performance. There was a problem that it decreased. Further, when the reinforcing rib 12 is welded to the structural member 10, the turn-welded portion at the upper end portion of the reinforcing rib 12 is likely to become a structural defect due to overlap between the welding thermal residual stress and the deterioration of the heat-affected member material at the welding toe portion. However, there was a problem that the yield strength and fatigue performance were reduced. Such a problem is caused by the structural member 10
It is common to many joint structures in which the reinforcing ribs 12 are T-welded to each other, and even in the Japan Steel Structure Association "Guidelines for Fatigue Design of Steel Structures and Descriptions", joints with fillet or groove welded gussets are used. It is pointed out that due consideration is given to the design because it will reduce the yield strength and fatigue performance of steel members.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and can significantly reduce the stress concentration at the toe portion of a plate-shaped member such as a reinforcing rib, and also the plate-shaped member. Since the members are welded, the residual heat stress of the welding can be relieved significantly, and as a result, the yield strength and fatigue performance can be greatly improved compared with the conventional structure. A joint structure between a plate-shaped member and an anchor bolt. It was made to provide the body.

[0005]

DISCLOSURE OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, is a bonded structure in which another plate-shaped member is welded to the surface of a structural member to project therefrom. -Shaped member is a reinforcing rib protruding in a T-shape extending in the principal stress direction of the structural member, and the end portion of the reinforcing rib in the principal stress direction extends in a direction away from the principal stress direction along the surface of the structural member. It is characterized by being bent. In addition, it is preferable that the end portion of the reinforcing rib in the main stress direction is curved and relaxed, and particularly, it is preferable that the reinforcing rib is bent to be perpendicular to the direction of the main stress.

The above structural member may be provided with a joining flange or a base plate, and the plate-like member may be provided between the structural member and the joining flange or the base plate, or the plate-like member may be provided. It may be for attaching a joint. Further, a plate-shaped member may be used for attaching the secondary member. The present invention is also a joined structure in which an anchor bolt extending in the principal stress direction is welded to the surface of a structural member, and the end portion of the anchor bolt in the principal stress direction is the main stress along the surface of the structural member. It can also be applied to a form bent in a direction away from the direction.

As described above, according to the present invention, the end portion (stop end portion) of the plate-like member such as the reinforcing rib is preferably bent in an inverted J-shape in a direction away from the principal stress direction of the structural member. The rigidity of the end of the plate member is reduced. As a result, when a load is applied to the structural member, the stress concentration near the end of the plate-shaped member is greatly alleviated, and since the plate-shaped member is welded, the welding heat near the end of the plate-shaped member is reduced. Residual stress can be relaxed. As a result, it is possible to significantly improve the proof stress and fatigue performance of the bonded structure as compared with conventional ones. Preferred embodiments of the present invention will be shown below. In the following embodiments, the plate-shaped member is a reinforcing rib, and is projected on the surface of the structural member by welding.

[0008]

1 is a perspective view showing a first embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a plan view thereof. is there. In this embodiment, the structural member 1 is a pedestal structure made of steel pipe, and 5 is a base plate for fixing the structural member 1 to a foundation. Between the structural member 1 and the base plate 5, a reinforcing rib 3 bent in an inverted J shape.
Is projected into a T-shape by T-welding.

The principal stress direction of the structural member 1 is the vertical direction in FIG. As shown, these reinforcing ribs 3 extend in the principal stress direction of the structural member 1 as a whole. Also, the upper end 4 of the reinforcing rib 3 on the side far from the base plate 5
Is curved and bent along the surface of the structural member 1 until it becomes perpendicular to the principal stress direction. The reinforcing rib 3 is welded to the structural member 1 and is also rotated and welded to the base plate 5. To ensure welding,
It is preferable to provide a scar wrap at the inner corner of the reinforcing rib 3.

In the joint structure having this structure, the end portion 4 of the reinforcing rib 3 is reverse J in the direction away from the principal stress direction of the structural member 1.
Since it is bent in a letter shape, the end portion 4 of the reinforcing rib 3 can have a low rigidity structure. As a result, the stress concentration at the end portions 4 of the reinforcing ribs 3 is significantly relieved, the welding heat residual stress in the welded portion is also relieved, and the yield strength and fatigue performance of the bonded structure are significantly improved.

In order to sufficiently bring out this effect, it is preferable that the radius of curvature r of the end portion 4 of the reinforcing rib 3 is set to 3 times or more the plate thickness t. If the radius of curvature r is smaller than this, material deterioration is likely to occur when the reinforcing rib 3 is curved,
Moreover, the effect of lowering the rigidity is also reduced. Cut off the width of the reinforcing rib 3 diagonally so as to narrow toward the end 4,
The rigidity of the end portion 4 can be further reduced.

In each of the embodiments, the pipe forming the structural member 1 is shown as a round steel pipe, but it may be a square pipe, and the structural member 1 may be made of a shaped steel.

When the bonded structure of the present invention was analyzed by FEM, it was confirmed that the stress concentration around the reinforcing ribs 3 was significantly alleviated as compared with the conventional structure in which the ends were not bent.

In the second embodiment shown in FIG. 4, the reinforcing rib 3 is used.
Is slightly inclined with respect to the principal stress direction of the structural member 1. Also in this case, the end 4 is to be largely bent in an inverted J shape.

In the third embodiment shown in FIG. 5, the inverted J-shaped reinforcing ribs 3 as shown in FIG. 1 are back-to-back,
The reinforcing rib 3 has a substantially T shape.

It is preferable that the end portion 4 of the reinforcing rib 3 is curved and relaxed as shown in the drawings, but it is also possible to bend it in a straight line. In this case as well, the end portion 4 of the reinforcing rib 3 has a low rigidity with respect to the main stress of the structural member 1, so that the same effect as described above can be obtained. However, since new stress concentration occurs in the bent portion, it is preferable to relax and bend in a curved shape.

(Joined Structure of Structural Member and Reinforcement Rib for Attaching Joint) The fourth embodiment shown in FIG. 6 is a joint for joining two structural members 1 (steel pipes) to each other in an end in the main stress direction. Reinforcing rib 3 in which part 4 is bent along the surface of structural member 1
Is used. In the case of adopting such a joining structure, conventionally, as shown on the right side of FIG. 6, a flat plate steel pipe joint 7 was welded to the end of each steel pipe and connected with bolts or rivets. Stress concentration occurs at the end of the steel pipe joint 7. However, as shown on the left side of FIG.
By using the reinforcing ribs 3 that are bent, the stress concentration can be relieved and the welding heat residual stress can be relieved.

(Joined Structure of Structural Member and Reinforcing Rib for Attaching Secondary Member) The fifth embodiment shown in FIG. 7 is a reinforcing member for attaching the secondary member 8 to the side surface of the steel pipe which is the structural member 1. The rib 3 is provided in a T shape by welding. The reinforcing ribs 3 also extend in the principal stress direction of the structural member 1, and both upper and lower ends thereof are bent in an inverted J shape in a direction away from the principal stress direction of the structural member 1. As compared with the conventional structure shown in FIG. 8, the stress concentration at the end portion can be relaxed and the welding heat residual stress can be relaxed as in the other embodiments.

The sixth embodiment shown in FIG. 9 is an application of the present invention to a horizontal frame gusset structure. In this case, the structural member 1 is an I-shaped steel installed horizontally, and the principal stress direction is horizontal. A reinforcing rib 3 whose both ends are bent so as to escape from the main stress direction is horizontally T-welded to the side surface of the structural member 1, and a secondary member 8 extending in the horizontal direction is fixed to the reinforcing rib 3. . FIG. 10 shows a conventional horizontal horizontal gusset structure, and since flat plate-shaped reinforcing ribs are used, stress concentration at the end is large, but with the structure of FIG. 9, stress concentration at the end is increased. It is possible to relax, and also it is possible to relax the welding heat residual stress.

The seventh embodiment shown in FIG. 11 is an application of the present invention to an anti-tilt gusset structure. In this case as well, the structural member 1 is I-shaped steel installed horizontally, but the principal stress direction is the vertical direction. Reinforcing ribs 3 having both ends bent are vertically T-welded to the side surface of the structural member 1, and a secondary member 8 extending obliquely upward is fixed. As compared with the conventional anti-tilt gusset structure shown in FIG. 12, stress concentration and welding heat residual stress at the ends of the reinforcing ribs 3 are alleviated.

(Joining Structure of Structural Member and Anchor Bolt) Although all the joining structures described above were joining structures of the structural member 1 and the reinforcing ribs, the eighth embodiment shown in FIG. The form is that the anchor bolt 9 is attached to the end of the structural member 1.
Are welded together. Also in this case, the anchor bolt 9
Extend in the principal stress direction of the structural member 1. In the conventional anchor structure shown in FIG. 14, stress concentration occurs at the ends of the anchor bolts. However, as shown in FIG. 13, the ends of the anchor bolts 9 in the principal stress direction are subjected to the principal stress along the surface of the structural member 1. By bending so as to escape from the direction, the stress concentration is relaxed and the welding heat residual stress is relaxed.

In order to confirm the effects of the present invention described above,
When a fatigue strength test was conducted, the test body corresponding to the prior art was about grade G in the design life curve of the railway bridge design specification, whereas the test body corresponding to the present invention was grade A to B. This is equivalent, and it was confirmed that the structure of the present invention significantly improved the fatigue strength.

[0023]

As described above, according to the present invention, the stress concentration and welding heat residual stress at the toe of the plate-shaped member in the joint structure can be relaxed, and the yield strength of the joint structure can be reduced. It is possible to significantly improve fatigue performance and fatigue performance. For this reason, the present invention can greatly contribute to the improvement of reliability in a wide range of applications as shown in the embodiments including a steel tube column foot anchor structure such as a lighting pole.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment.

FIG. 2 is a front view showing the first embodiment.

FIG. 3 is a plan view showing the first embodiment.

FIG. 4 is a perspective view showing a second embodiment.

FIG. 5 is a perspective view showing a third embodiment.

FIG. 6 is a perspective view showing a fourth embodiment together with a conventional structure.

FIG. 7 is a perspective view showing a fifth embodiment.

FIG. 8 is a perspective view showing a conventional structure corresponding to a fifth embodiment.

FIG. 9 is a perspective view showing a sixth embodiment.

FIG. 10 is a perspective view showing a conventional structure corresponding to the sixth embodiment.

FIG. 11 is a perspective view showing a seventh embodiment.

FIG. 12 is a perspective view showing a conventional structure corresponding to a seventh embodiment.

FIG. 13 is a perspective view showing an eighth embodiment.

FIG. 14 is a perspective view showing a conventional structure corresponding to the eighth embodiment.

FIG. 15 is a perspective view showing a conventional bonded structure.

FIG. 16 is a perspective view showing another conventional joining structure.

[Explanation of symbols]

1 Structural member 3 Reinforcing ribs that are plate-shaped members 4 Ends of reinforcing ribs 5 base plate 6 bolts 7 Steel pipe fittings 8 Secondary member 9 Anchor bolt 10 Structural member in the prior art 11 Base plate for bolt connection in the prior art 12 Reinforcing rib in the prior art

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masakazu Sugimoto             20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel shares             Company Technology Development Division (72) Inventor Masayuki Okimoto             2-6-3 Otemachi, Chiyoda-ku, Tokyo New Japan             Steelmaking Co., Ltd. (72) Inventor Tetsumi Kondo             2-6-3 Otemachi, Chiyoda-ku, Tokyo New Japan             Steelmaking Co., Ltd. (72) Inventor Shiro Kita             Yoshimo 1-10-1 Yurakucho, Chiyoda-ku, Tokyo             Topole Co., Ltd. (72) Inventor Masafumi Higasa             3-1-1, Sellobori, Nishi-ku, Osaka-shi, Osaka Prefecture             Ceremony company Inaba Denki Seisakusho F-term (reference) 2D046 AA14                 2E125 AA02 AB17 AC16 AD06 AE13                       AG06 AG12 AG52 AG57 BB03                       BB22 BB35 BC02 BD01 BE08                       BF01 BF04 BF08 CA05 CA90                       CA96                 4E081 YB04

Claims (6)

[Claims] 1. A joined structure in which another plate-shaped member is welded to the surface of a structural member to project, and the plate-shaped member is projected in a T shape extending in the principal stress direction of the structural member. A joint structure, which is a reinforcing rib, wherein an end portion of the reinforcing rib in the principal stress direction is bent along a surface of the structural member in a direction away from the principal stress direction. 2. The joined structure according to claim 1, wherein the end portion of the reinforcing rib in the principal stress direction is bent to be perpendicular to the principal stress direction. 3. The structural member according to claim 1, wherein the structural member is provided with a joining flange or a base plate, and the reinforcing ribs are provided between the structural member and the joining flange or the base plate. The joined structure according to. 4. The joint structure according to claim 1, wherein the reinforcing rib is for attaching a joint. 5. The joined structure according to claim 1, wherein the reinforcing rib is for attaching a secondary member. 6. A joint structure in which an anchor bolt extending in the principal stress direction is welded to the surface of a structural member, and the end portion of the anchor bolt in the principal stress direction is welded along the surface of the structural member. A joined structure characterized by being bent in a direction away from the direction.