JPS61219481A - Welding method for structural member for column and beam - Google Patents

Abstract

PURPOSE:To reduce the deformation of structural member due to welding heat, by forming the joining surfaces of a column and a beam into flat ones, smoother than a specific roughness, and welding only a part of joining surfaces to be subjected to tensile stress. CONSTITUTION:In welding a column 1 and a beam 2 together, a range to be subjected to tensile stress 6 with respect to the neutral axis 7 of beam 2, is perfectly welded 3, 4. On the other hand, a range 5 to be subjected to compressive stress, is left without welding, and the joining surfaces of column 1 and beam 2 are formed into flat surfaces equal to or smoother than at least 30 S roughness. The welding deformation due to welding heat is reduced, because the range to be subjected to compressive stress is not welded. Further, because the unwelded part 5 is provided with proper roughness, the parts are brought into perfectly tight contact with each other, and then the characteristics of rigidity and fatigue strength are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a joining method (-) in which a non-welded portion is intentionally left at the joining boundary between a pillar and a beam in a pillar-beam structural member constructed by welding.

[Technical background of the invention and its problems]

Conventionally, as shown in FIG. 5, structural members such as a column 1 and a beam 2 made of, for example, section steel are generally subjected to full penetration welding 3 and 4 at their joints. The increase in welding amount due to complete penetration inevitably induces welding deformation, that is, bending deformation, shrinkage deformation, and twisting deformation.In fact, the processing number to correct these deformations = accompanying The occurrence of cracks and material deterioration cannot be ignored.Especially when welding is carried out in extremely poor work environments such as assembly sites, it is difficult to use large jigs and tools for groove alignment, or welding Since the position cannot be freely selected (upward, horizontal, vertical welding, etc.), the larger the amount of welding, the more likely welding defects such as welding defects will occur (there are two types).

Similarly, when an external force normally acts on a joint component of a plate structural member as shown in FIG. Therefore, it can be considered exactly the same as the column-beam structural member shown in FIG. In this case, considering welding on-site, the welding between member 9 and member 10 is performed by welding 11
Consisted of. That is, welding from the opposite side to the load direction 5 is also considered, but this is generally not done because the welding posture is upward and the incidence of welding defects increases.

The problems in this case are exactly the same as those occurring in the above-mentioned column-beam structural members, such as welding deformation and defects easily occurring at the weld root.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to reduce various thermal deformations that occur during welding,
The object of the present invention is to provide a highly reliable welding method for column-beam structural members or similar joint members by reducing the incidence of welding defects.

[Summary of the invention]

In order to achieve the above-mentioned object, the method for joining structural members of columns and beams according to the present invention is such that the part that receives compressive stress with respect to the neutral axis of each welded joint to be joined is a non-welded part that is not welded, and the tensile stress is reduced. The receiving part forms a welded part by welding. In particular, for surfaces subject to compressive stress, the joint surface is finished smooth and welding is performed without creating a groove gap in order to ensure smooth stress transmission between members.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
FIG. 2, FIG. 3, and FIG. 4 are diagrams for explaining an embodiment of the method for joining column-beam structural members according to the present invention.

Regarding the welding between the members 1 and 2 to be joined by welding in Fig. 1, regarding the neutral axis 7 of the beam assembly 2, the range where the tensile stress acts as shown in 6 is a complete weld with a groove as before. , welding shall not be performed in the range where compressive stress 5 acts. In this case, column 1 and beam 2
The joint surfaces of the welds will be machine-finished or grinded to a similar level of smoothness to efficiently transmit compressive stress on the non-welded surfaces.

FIG. 7C2 shows the case where there is this groove gap. Assuming that this groove gap is δ, Figs. 8 and 9 show that the stiffness of the joint (7
As shown in the figure, a uniform load 5 is applied to a beam (defined as the slope of the load and deflection curve of the beam), as well as experimental results on 107 times fatigue strength from a cyclic loading test. As is clear from Fig. 8, the conventional structure h
Although a slight decrease in rigidity is observed compared to /H = 1.0, approximately the same result is observed when the groove gap is δ = 0.
When having a groove gap of 2 dews, the rigidity and
The decrease in fatigue strength is significant. This is thought to be due to the presence of a groove gap, which prevents effective load transfer from occurring on the compressive stress side (secondly, because the column and beam do not contact each other). Figure 10 shows that a surface roughness of about 308 is required for load transfer to take place.This phenomenon is caused by the shrinkage of welds 3 and 4, which causes the non-welded surface to shrink even if there is a roughness of about 308. This is thought to be due to almost complete contact.

In the embodiment shown in Fig. 1, the invention in which the column 1 and the beam 2 are simply joined by welding 3.4 (two are shown). However, such welding on only one side about the neutral axis It is easy to cause bending deformation as shown in the figure, and a jig to prevent bending deformation is usually required during welding (no two-way alignment is required).Therefore, in on-site welding, weld upwards, which reduces workability and reliability. Another example shown in Fig. 2 shows a method in which the welding 8 is performed in a downward position by reversing the parts during in-factory manufacturing to prevent bending and deformation of the beam without a special restraint jig. Even in this case, if the non-welded surfaces are in perfect contact, the same effects as in FIGS. 8 and 9 will be shown in terms of rigidity and fatigue strength.

Furthermore, it is clear that the application of the present invention is not limited to columns and beam structural members, but also produces similar effects and effects in FIGS. 3 and 4.

〔Effect of the invention〕

As described above, according to the present invention, the part of the welded joint to be joined that is subjected to compressive stress with respect to the neutral axis is welded.
In addition, the non-welded surface is machined to 308 or more so that the members to be joined are in complete contact with each other, and welding is performed with the members in contact with each other. This reduces the air volume per welding area, reduces welding thermal deformation, and enables highly reliable welding with a low weld defect rate.It also improves the rigidity and fatigue strength of the joint compared to conventional methods. A similar method for joining structural members of columns and beams can be provided.

[Brief explanation of the drawing]

1, 2, 3, and 4 are diagrams for explaining the method of welding and joining column and beam structural members according to the present invention, and FIG.
Figure 6 is a diagram for explaining the conventional welding method for beam and column structural members, Figure 7 is the shape of the column and beam structural members used to explain Figures 8 and 9; Figure 9 shows the effects of the groove gap and weld length on the weld joint stiffness of column-beam structural members. Figure 9 shows the effects of the groove gap and weld length on the fatigue strength of weld joints of column-beam structural members A diagram showing the impact,
FIG. 10 shows experimental results showing the relationship between the surface roughness of the joint and the contact surface crimping rate of the column-beam joint. 1. Pillar 2. Beam 3, web weld 4. flange welding part 5,
External load 6, beam bending stress due to external load, neutral axis 8. Fillet welding 9, vertical member
10. Horizontal member 11, groove welding
12. Fillet welding 13, bending deformation 14.
Covering plate 15, welding route agent Patent attorney Noriyuki Chika (1 person) Figure 3 Figure 5

Claims (1)

[Claims] The joint surfaces of the columns and beams that are to be joined to each other are formed into smooth surfaces of at least 30S or more, and after they are brought into contact, the joints that receive tensile stress relative to the neutral axis of the beams are welded. A method for welding structural members of columns and beams, characterized by: