JPH0425458Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to box-shaped cross-section columns with excellent toughness for use in buildings. The smaller the width-thickness ratio, the better the toughness of a box-shaped cross-section column. In other words, in a case of a constant width, the thicker the thickness, the less likely local buckling will occur and the better the toughness will be. When designing buildings, it was necessary to increase the thickness of the plates and reduce the width-to-thickness ratio in order to maintain good toughness against earthquake stress and to ensure a safety factor at all times. However, this had the disadvantage of increasing the weight of the pillar and making it expensive. This design solves the above drawbacks, delays the occurrence of local buckling in the pillars adjacent to the shikiguchi despite the large width-to-thickness ratio, and reduces the amount of deformation while maintaining the yield strength even after buckling. It is an object of the present invention to provide a box-shaped cross-section column having a horizontal stiffener which increases the stiffness and improves toughness. In order to achieve the above object, the configuration of this invention is such that a right-angled triangle is formed on the inner surface of a column 1 having a box-shaped cross-section, with a right-angled portion 3 in the column cross-section sandwiched therebetween, and approximately half the width B of the column cross-section. The two sides of the horizontal stiffener 2 are welded, and the horizontal stiffener 2 has a width of 1/4 to 1 of the width B of the cross section of the column.
From a box-shaped cross-section column having a horizontal stiffener provided at a distance D of twice the width and extending outward from the end of the column beam joint 5 within a length L that is 1 to 1.5 times the width B. It is what it is. Hereinafter, embodiments of this invention will be described based on the drawings. Reference numeral 1 denotes a box-shaped cross-section column having a thickness t that is relatively thin relative to the width B. As shown in FIG. Two sides of a right triangular horizontal stiffener 2 are welded to approximately 1/2 the width B of the column 1. The welded portion 4 is left in contact with as much of the column plate surface as possible. By doing so, the rigidity of the plate element of the box-shaped cross-section column 1 is increased, and the occurrence of local buckling can be delayed compared to when there is no stiffener. In FIG. 2, reference numeral 5 denotes a joint between a beam 6 and a pillar 1, and a horizontal stiffener 2 is provided at an adjacent portion extending outward from the end of the joint 5. The horizontal stiffener 2 is provided within a distance L of 1 to 1.5 times the width B of the box-shaped cross section from the end of the joint 5 toward the outside, and is provided at a distance L greater than that. Even if it is set to 1.5 times or more, the effect of improving toughness is small and it is not necessary to increase the toughness by 1.5 times or more.
That is, it is effective that the distance L for providing the horizontal stiffener 2 is 1 to 1.5 times the width B from the end of the joint 5 toward the outside. In addition, if the distance D between the horizontal stiffeners 2 is less than 1/4 of the width B of the box-shaped cross section, local buckling will occur in the column 1 portion other than the stiffening portion where the horizontal stiffener 2 is provided, improving the toughness. If the number of stiffeners is 1 or more, there is no clear difference between the stiffener and the stiffener, and effective stiffening cannot be achieved. As is clear from the load-deformation curve (see table below) in the experimental results shown in Figure 3, the width B

[Table] Items with smaller spacing of 1/4 or more of width B (No. 2~
No. 4) does not have a stiffener (No.
1) It is possible to increase the amount of deformation while maintaining the proof stress even after buckling (A ₂ to _{A 4} ) than (buckling (A 1 )), and therefore it is smaller than width B and 1 of width B. /Four
A spacing larger than this is effective for improving toughness. This design has a configuration in which the two sides of the horizontal stiffener 2 in the form of a right triangle are welded to approximately 1/2 the width B of the column cross section across the right angle part 3 of the column cross section, as described above. The horizontal stiffener 2 has a strong resistance to twisting caused by horizontal forces, and the area of the horizontal stiffener 2 is only 1/2 that of a square one, making it lightweight, and the weight of the box-shaped cross-section column 1 is heavy. At the same time, it is possible to prevent the inner surface of the adjacent part of the joint 5 of the box-shaped cross-section column 1 with an interval D smaller than the width B in the column cross section and at least 1/4 of the width B, and from the end of the joint 5 to the outside. Since the horizontal stiffener 2 is provided within the range of length L that is 1 to 1.5 times the width B in the direction of In addition to delaying the occurrence of
Even after buckling, the amount of deformation can be increased while maintaining the yield strength, and the toughness can be improved.
Therefore, the box-shaped cross-section column with the horizontal stiffener of this invention has the same toughness as one with a large width-to-thickness ratio as one with a small width-to-thickness ratio, so it is more durable than one without a horizontal stiffener. Box-shaped cross-section columns with thin plate thickness can be used, reducing the weight of the steel frame and reducing costs.

[Brief explanation of the drawing]

Figures 1 and 2 show one embodiment of this invention; Figure 1 is a cutaway plan view, Figure 2 is a partially cutaway front view, and Figure 3 is a box with a width-thickness ratio of 44.4. It is a graph showing a load-deformation curve of a shaped cross-section column. 1...Column, 2...Horizontal stiffener, 5...Shiguchi, B...Width, D...Distance, L...Length.

Claims (1)

[Scope of utility model registration request] Two sides of a right-angled triangular horizontal stiffener 2 are welded to the inner surface of a column 1 having a box-shaped cross section at a length approximately half the width B of the column cross section, with the right angle part 3 in the column cross section in between. 1/4 to 1 of the width B of the column cross section
A box-shaped cross-section column having horizontal stiffeners provided at twice the interval D and extending outward from the end of the column beam joint 5 within a length L that is 1 to 1.5 times the width B.