JPH041373A - Steel structure - Google Patents

Abstract

PURPOSE:To reduce vibrations and converge them at an early stage by laminating dead soft steel materials having a yield point lower than a base material to the end sections of the posts and girders of a steel structure consisting of the posts and the girders, burdening bending stress generated at the time of an earthquake by the laminated dead soft steel materials and plasticizing the dead soft steel materials. CONSTITUTION:The posts 11 and girders 12 of a steel structure are composed of H steel consisting of high tension steel for welding. Dead soft steel 13 having a low yield point and large elongation capacity in a plastic region is laminated and joined as flanges at both ends of the girders 12. One part of bending stress generated at the time of an earthquake, etc. is burdened by the soft steel 13, and plasticized. Accordingly, the vibrations of the structure are reduced, and converged at an early stage.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to steel structures.

(Prior Art) Steel structures are designed so that they will not be damaged by small to medium earthquakes that often occur or strong winds such as typhoons, and the structural steel will remain within an elastic range.

However, even if the structural steel frame is within the elastic range, steel structures have low damping during vibration, so in the case of skyscrapers, towers, etc., the amount of deformation due to vibration is particularly large, and vibrations can continue for several tens of seconds.

In order to suppress and control this vibration, various h-methods have been proposed, such as an active control device using a computer and a viscous damper.

(Problems to be Solved by the Invention) However, the vibration reduction method according to the above-mentioned conventional technology requires very advanced analysis technology and the need to incorporate special products and equipment into the structure, which tends to complicate the design and increase construction costs. It is in.

The present invention has been proposed in view of the problems of the prior art, and its purpose is to reduce vibrations in steel structures with a simple configuration and low construction cost, and to quickly reduce vibrations in steel structures. The purpose is to provide a steel structure that can be converged.

(Means for Solving the Problems) In order to achieve the above object, the steel structure according to the present invention G has a steel structure C consisting of columns and beams, which has a much higher yield than the base material at the ends of the columns and girders. It is constructed by laminating extremely soft steel materials with low points.

(Function) According to the present invention, in a steel frame structure having columns and beams made of ordinary steel, the ends of the columns and beams, which are subject to relatively large strains due to earthquakes and strong winds, are By laminating extremely soft steel materials that have a yield point much lower than steel materials and have a large elongation capacity in the plastic region, the extremely soft steel materials bear part of the bending stress that occurs during earthquakes, etc., and become plastic. By doing so, a restoring force characteristic with large damping can be obtained, the vibration of the structure can be reduced, and it can be converged quickly.

(Example) The present invention will be described below with reference to the illustrated embodiments.

Figure 4 shows a rigid frame structure consisting of columns (1) and beams (2) using H-beams, which are a common frame type for steel structures.

High-strength steel for welding (SM50σA3
300 kg/c-d or more, yield point 33 kg/mm2) is used.

The relationship between the bending moment applied to the frame member and the strain generated on the member surface when such a frame vibrates greatly in the elastic range is as shown in Figure 2. The third diagram also shows a state in which the width of the horizontal displacement gradually decreases with the passage of time.

Since the framework has low damping performance, the vibration continues for a long time.

FIG. 1 shows the frame of the steel structure according to the present invention, and shows a column (1
1) and 粱(12) are high tensile strength steel materials for welding (5M50.σ
.

= 3300kg/cd, yield point 33kg/mm
”) is composed of H-shaped dates.

The flanges at both ends of the beam (12) have a yield point of 5 to 1.
About 5kg/mm”Cσy=500~1500kg/
Very mild steel (13), which has a yield point of about cffl, which is much lower than the yield point of structural steel materials used for boats and has a large elongation ability in the plastic region, is laminated and joined together.

As a method for laminating and joining the extremely soft @ (13), thin materials may be welded together, or bolt C joining may be used.

Furthermore, fence boards that are laminated and manufactured in advance like clad rope may also be used. Furthermore, the locations where extremely mild steel (13) is laminated and joined are not limited to the ends of the four frames, but can be anywhere within the steel structure where relatively large distortions occur. Other parts may be the upper and lower ends of columns, the shafts of braces, or the joints between columns and beams.

When the frame shown in the first circle is subjected to a load in the hydraulic direction due to an earthquake or strong wind, the bending moment in the elastic region of the member laminated with extremely soft i (13) and the strain on the surface The relationship is as shown in Figure 2C, which is the relationship between the bending moment and strain of only the original high-strength steel member without super-soft E (13) laminated (see Figure 2A), and the relationship between the bending moment and strain of the original high-strength steel member without super-soft E (13) laminated (see Figure 2A), and the relationship between extremely soft # (13) This results in a state in which the relationship between the bending moment of the part and the strain on the surface (FIG. 2B) is cumulative.

As is clear from the above figure, the original member remains in the elastic range, but the ultra-soft 1 (13), which has a very low yield point and is laminated on both ends of the member, collapses early. Shown at 2C Seki-
It has 4 history loops.

This hysteresis loop improves the vibration damping performance of the framework and helps reduce the horizontal displacement amplitude.

The third circle shows a state in which the amplitude of the horizontal displacement of the frame in Figure 1 gradually decreases over time, and the displacement amplitude converges earlier than in the case shown in Figure 6. ing.

(Effects of the Invention) According to the present invention, as described above, by laminating extremely mild steel materials with a yield point much lower than that of the base material on the columns and ends of the steel frame structure consisting of columns and beams, In addition to reducing the vibrations of steel structures, the vibrations are quickly contained, and there is no need to incorporate advanced design technology or special products or mechanisms, which simplifies the configuration and reduces construction costs. The structure of the present invention can be easily incorporated into existing steel structures.

[Brief explanation of the drawing]

Part 1 shows the framework of a steel structure according to the present invention. Figure 2A shows the relationship between the bending moment of only the high-strength steel members in the framework and surface strain. Relationship diagram between bending moment of part and surface strain, 2C
The figure shows the relationship between the bending moment in the elastic region and the surface strain of a member made of laminated extremely mild steel, Figure 3 shows the vibration damping performance of the structure, and Figure 4 shows the framework of a conventional steel structure. Fig. 1 shows a front view of the engine, and a fifth view of the load-displacement relation diagram. (11)...Column, (13)...Extremely mild steel.

Claims (1)

[Claims] The columns and ends of a steel structure consisting of columns and beams are laminated with extremely mild steel materials that have a much lower yield point than the base material, and the laminated extremely mild steel materials bear the bending stress that occurs during an earthquake and become plastic. 1. A steel structure characterized in that the steel structure is constructed so as to obtain restoring force characteristics with large attenuation.