JPS6146094Y2 - - Google Patents

Description

[Detailed explanation of the idea]

This invention relates to the improvement of a steel material for tensile reinforcement that is stretched between opposing base materials of a structure, for example, a steel frame building. Steel materials for tension reinforcement include flat bars, angles, channels, etc., and these are generally attached to the base metal by welding a flat gusset plate 10 to the base metal 12, as shown in Figure 1. Then, the steel material 1 is attached to this gusset plate.
A fastener 11 such as a stud or bolt nut that penetrates the end of the
It is carried out by. Therefore, a stopper insertion hole is drilled at the end of the steel material, and the cross-sectional area passing through the center of this insertion hole and perpendicular to the longitudinal direction of the steel material is as shown in the following table in the case of a flat bar. On average, the cross-sectional area of the steel material is 76.72% of the area where no penetration holes are drilled.

【table】

[Table] As shown above, conventional steel materials for tensile reinforcement have a cross-sectional defect due to the stopper insertion hole at the end where the stopper is attached.On the other hand, since tensile stress acts uniformly on the entire steel material, The tensile strength of a steel material is determined by the size of the cross-sectional area in the direction perpendicular to the longitudinal direction, passing through the center of the stopper insertion hole at the end of the steel material where the cross-sectional area is the smallest, so as shown in the table above. Average effective usage rate of steel material (cross-sectional area at center position of stopper insertion hole/
(cross-sectional area of the position where the stopper insertion hole is not provided)
is 76.72%, which means that approximately 23% of steel is wasted. This idea was created in view of the above points, and aims to effectively increase the tensile strength of the steel material by attaching a steel plate by welding to the stop attachment surface of the main body of the steel material for tensile reinforcement. . Hereinafter, an embodiment of this invention will be described with respect to a flat bar. In Fig. 2, a reinforcing steel plate 2 with a predetermined thickness (hcm) is attached to the fastener mounting surface at the end of the flat bar body 1 by welding its both ends. match the width,
Further, by forming both ends of the steel plate 2 into chevron-shaped uneven edges 2a and increasing the weld length at both ends of the steel plate 2, the attachment of the steel plate 2 to the main body 1 is ensured. Then, a stopper insertion hole 3 penetrating through the steel plate 2 and the main body 1 is bored at a predetermined position of the steel plate 2. Next, a method for setting the thickness h of the reinforcing steel plate 2 will be explained based on FIG. 3. First, when determining the cross-sectional area loss due to the stopper insertion hole 3 as a standard, T: short-term allowable tensile strength of the flat bar body 1 (ton) A ₁ g: cross-sectional area of the flat bar body 1 (cm ² ) Fm: of the flat bar body 1 Assuming that the standard strength is "SS41" whose material does not easily change due to welding, and assuming 2.4 ton/cm ² , T = Fm x A ₁ g = 2.4 ton/cm ² x A ₁ g. T': Maximum tensile strength (tons) to be borne by the fastener attachment part of the flat bar body 1 b: Width of the flat bar body 1 and reinforcing steel plate 2 (cm) φ: Inner diameter of the fastener insertion hole 3 (cm) m: Number of fastener insertion holes 3 in the width direction t: Thickness of flat bar body 1 (cm) h: Thickness of reinforcing steel plate 2 (cm) Fa: Standard strength of reinforcing steel plate 2, assuming 2.2 ton/cm ²・T'=(b-m・φ)(t+Fs/Fmh)×F
m = (b-m・φ) (t+2.2h/2.4
) ×2.4ton/ ^cm2 . And since T'≧T, (b-m・φ)(t+2.2h/2.4) ×2.4≧2.4×A:g ∴h≧2.4/2.2(A ₁ g/b- m・φ−t
) Next, the welding strength of the reinforcing steel plate to the flat bar is determined based on the following: le: Effective length of welding at one end of the reinforcing steel plate 2 (cm) Tw: Short-term allowable yield strength at the welding point at one end of the reinforcing steel plate 2 (ton) Ts: Tensile strength to be borne by the reinforcing steel plate 2 (tons) fw: Short-term allowable stress per unit length for fillet weld size S, according to the design standards method specified by the Minister of Construction.

becomes [formula]. S: The size of the fillet of the lap joint between the flat bar 1 and the reinforcing steel plate 2, which should be the same as the thickness h of the reinforcing steel plate 2. Here, if the inclination angle of the uneven edge 2a of the reinforcing steel plate 2 is 45°, le=2(√2b−2h) Ts=b・h×2.2ton/ ^cm2 . And since Ts≦Tw, b・h×2.2≦1.9595912(√2b−2h)
×h ∴ h≦0.1457b Therefore, the thickness (hcm) of the reinforcing steel plate 2 is determined by the following formulas: h≧2.4/2.2 (A ₁ g/b-mφ-t) and h≦0.1457b All you have to do is set it so that it satisfies. Furthermore, FIG. 4 shows an embodiment in which the steel material for tensile reinforcement is a channel, in which a reinforcing steel plate 5 is attached by welding to the stopper attachment surface at the end of the channel body 4, and a stopper insertion hole 6 is bored. It was established. Further, FIG. 5 shows an embodiment of the angle, in which a reinforcing steel plate 8 is attached by welding to the stopper attachment surface at the end of the angle main body 7, and a stopper insertion hole 9 is bored. As explained above, in the steel material for tension reinforcement of this invention, a reinforcing steel plate is attached by welding to the stopper mounting surface at the end of the steel material body, a stopper insertion hole is bored, and the center of the insertion hole is Since the cross-sectional area passing through the steel material is made to be the same as or larger than the cross-sectional area of the main body of the steel material, in the conventional steel material for tension reinforcement, the cross-sectional area of the stopper insertion hole at the end of the steel material is the minimum, and the The tensile strength of steel materials is determined by the maximum allowable yield strength, and steel materials have not been used effectively. However, according to the steel material of the present invention, the tensile strength of the steel material is determined by the maximum allowable yield strength of the steel material body in the part where the insertion hole is not provided. Since the maximum tensile strength is determined by the tensile strength of the steel material, the steel material can be used effectively and increased, safety is improved, and the cost per unit tensile strength can be reduced, which is economical.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the attachment part of a conventional flat bar attached to a base material via a gusset plate, Fig. 2 is a partial perspective view showing an embodiment of the flat bar of the present invention, and Fig. 3 is a perspective view of the attachment part of a conventional flat bar attached to a base material through a gusset plate. FIG. 4 is a partial perspective view of the embodiment in a channel, and FIG. 5 is a partial perspective view of the embodiment in an angle. DESCRIPTION OF SYMBOLS 1...Flat bar main body, 2, 5, 8... Steel plate for reinforcement, 3, 6, 9... Stopper insertion hole, 10... Gusset plate, 11... Stopper, 12... Base material.

Claims (1)

[Scope of utility model registration request] A reinforcing steel plate is attached by welding to the stop attachment surface at the end of the main body of the tensile reinforcement steel material, which consists of a flat bar, angle, channel, etc., and a stop insertion hole is drilled, and a cross section passing through the center of the insertion hole is formed. A steel material for tensile reinforcement of a structure, characterized in that the area is the same as or larger than the cross-sectional area of the main body of the steel material.