JPH04243683A - Unequal angle steel having bent face - Google Patents

Abstract

PURPOSE:To reduce the stress at a stiffener part (position of large stem) by forming a web in a nearly straight line form, forming a face to a nearly constant width and bending the face so that the installation position in the width direction of the face to the web is varied. CONSTITUTION:A bendable face 2 is formed so as to have a nearly constant width, and the face 2 is projected over a web 3 at the position of a large stem 4 by changing the installation position in the width direction of the face 2 to the web 3, and at other parts, the face 2 is projected downward, and the face 2 is formed so as to sharply bend only in the vicinity of the position of the large stem in the plane including the face 2. Accordingly, at the installation position (vicinity of the position of large stem) of the face 2 to a stiffener 5, stress is reduced, and the generation of crack at a welded part can be suppressed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaped steel suitable for use in the side longitudinal ribs of tankers carrying crude oil, etc., and more particularly to a scalene angle shaped steel with a bent face whose structure has been improved. Incidentally, the scalene angle steel with bent face of the present invention is
It can also be used as aggregate in steel structures consisting of surrounding walls and aggregates that support the surrounding walls.

0002

[Prior Art] Conventional ship side longitudinal ribs are shown in Figs. 10 and 11.
As shown in , it consists of a straight web 03 vertically connected to the ship's side shell 01 and a straight face 02 fixed orthogonally to the web 03, and is usually used to directly load crude oil, etc. To prevent residue from accumulating, the ribs of the tank are made of scalene angle steel (see the cross-sectional view in Figure 11), which is fixed so that the face 02 protrudes downward from the web 03. Equilateral angle bars such as those shown in Figure 14 are rarely used. Note that the face 02 and the large bone 04 are connected by a stiffener 05 at a portion where the longitudinal rib and the large bone 04 intersect.

0003

[Problems to be Solved by the Invention] By the way, in the conventional scalene angle steel used for ribs as described above,
As shown in c), it is known that higher stress occurs at the intersection between the web 03 and the face 02 (see arrow 06) than in the equilateral angle bar shown in FIG. That is, as shown in Fig. 12, in scalene angle steel,
Since the position of the centroid 0 of the cross section and the position of the shear center Q are different, when the shear force F acts as the pressure (water pressure, etc.) increases, a torsional moment M is generated, and stress due to bending [Fig. 13
(a)] is subjected to additional stress due to torsion (see FIG. 13(b)), which causes an increase in stress.

[0004] Since the stiffener 05 is attached to the above-mentioned intersection where high stress occurs, the stiffener 05
Stress concentration occurs at the weld between the face 5 and the face 02, and if the stress is large, cracks will occur in the weld, resulting in a significant decrease in the strength safety factor.

[0005] The present invention is an attempt to solve these problems, and when used in the longitudinal ribs of a ship, prevents the accumulation of residue and reduces the stress of scalene angle steel. The purpose of the present invention is to provide scalene angle steel with a bent face that can reduce stress at the stiffener part (large bone position) to the same level or more than that of equilateral angle steel by making use of the bias of do.

[0006]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the scalene angle steel with bent faces of the present invention is a scalene angle steel having a web and a face fixed perpendicularly to each other. The web is formed in a substantially linear shape, and the face is formed to have a substantially constant width, and the face includes the face in order to change the attachment position to the web in the width direction of the face. It is characterized by being bent inside.

[0007]

[Function] In the above-mentioned scalene angle steel with a bent face of the present invention, the face is formed into an appropriate bent shape in a plane including the face, and the attachment position of the face to the linear web in the width direction is adjusted. It changes to a predetermined position depending on the location, and when used as a longitudinal rib of a ship, it prevents debris from accumulating on the web, and
The stress distribution on the face surface can be changed so that the stress at the stiffener part (large bone position) is reduced.

[0008]

[Example] Hereinafter, embodiments of the present invention will be explained with reference to the drawings. Figures 1 to 5 show a scalene angle bar with a bent face as a first embodiment. Figure 1 is a perspective view thereof, and Figure 2 is a perspective view thereof. 3 is a cross-sectional view taken along the line A-A in FIG. 2, FIG. 4 is a cross-sectional view taken along the line B-B in FIG. 2, and FIG. 5 is a stress distribution diagram in the scalene angle steel shown in FIG. 3. , FIGS. 6 to 9 show scalene angle steel with bent faces as a second embodiment, FIG. 6 is a schematic side view, FIG. 7 is a sectional view taken along the line A'-A' in FIG. 6, and FIG. is a sectional view taken along arrow B'-B' in FIG. 6, and FIG. 9 is a sectional view taken along arrow B'-B' in FIG.
It is a stress distribution diagram in scalene angle steel.

As shown in FIGS. 1 to 5, in the first embodiment of the present invention, the scalene angle steel vertically joined to the side shell plate 1 has a web 3 formed in a substantially straight line and 3 and a bent face 2 fixed perpendicularly to the face 3. The bent face 2 is formed to have a substantially constant width, and the attachment position to the web 3 in the width direction of the face 2 is changed so that the face 2 is located above the web 3 at the position of the large bone 4. Protrusion (Fig. 3
), and in other parts, in order to make the face 2 protrude downward from the web 3 (Fig. 4) as in the conventional scalene angle steel, the face 2 is only located near the major bone position in the plane that includes the face 2. It is formed so that it bends sharply at
In other parts, it is formed into a straight line. That is, the shape of the face 2 is a linearly curved shape as shown in FIG. 2, and l1 is set to be sufficiently smaller than l2. As a result, at the attachment position of the face 2 to the stiffener 5 (near the large bone position), a torsional moment of almost equal absolute value acts on the cross-sectional shape in the opposite direction to the conventional one, and the face 2 and the web 3 Focusing on the intersection (arrow 6 in FIG. 5), stress due to bending and stress due to torsion cancel each other out. Note that the stress distribution in this case is as shown in FIG. Therefore, the stress at the welded portion between the face 2 and the stiffener 5 is reduced, and the occurrence of cracks at the welded portion is suppressed. By the way, when such a linearly bent face 2 is used, there is a part of the face 2 that protrudes below the web 3 (a part where the top surface of the face is low) as shown in FIG. It will not flow out and remain.

Next, a description will be given of a second embodiment of the present invention. As shown in FIGS. The steel is composed of a web 3 formed in a substantially straight line and a bent face 2 fixed perpendicularly to the web 3, and the bent face 2 is formed to have a substantially constant width. ing. In this embodiment, the attachment position of the face 2 to the web 3 in the width direction is changed, so that the face 2 protrudes above the web 3 at the position of the large bone 4 (FIG. 7), and the attachment position between the large bones 4 is changed. In the central part, the face 2 protrudes downward from the web 3 in the same way as the conventional scalene angle steel (Fig. 8). As shown,
It is formed by smoothly bending the shape of one period of the SIN curve. As a result, the torsional moments generated at the center and end portions between the large bones 4, 4 are in opposite directions, and their absolute values integrated in the longitudinal direction are equal to each other. (near), the torsional moment becomes zero.

Therefore, the stress distribution in this case becomes as shown in FIG. 9, and the stress at the welded portion of the stiffener 5 on the face 2 is reduced, and the occurrence of cracks at the welded portion is suppressed. .

By the way, even when such a SIN curve type face 2 is used, there is a portion of the face 2 that protrudes below the web 3 (a portion where the upper surface of the face is low) as shown in FIG. No residue will flow out of this area and remain.

[0013] In the above two embodiments, face 2
In order to drain the residue on the upper surface, the mounting position of the face 2 relative to the web 3 of the large bone 4 part is set higher, and the same position is lowered in other parts, but this is done only to prevent cracks in the stiffener 5. If appropriate, the bending of the face 2 may be reversed upward and downward.

[0014]

[Effects of the Invention] As described in detail above, according to the scalene angle steel with bent faces of the present invention, a face having a substantially constant width is formed so as to be bent within a plane including the face. , while maintaining the characteristic of scalene angle shape steel that it is difficult for residue to accumulate on the web, we reversely utilize the stress imbalance due to the torsional moment unique to scalene angle shape steel, and achieve the same or lower than that of scalene angle shape steel. By reducing the stress at the joint position on the face with other parts, suppressing the occurrence of cracks at the weld between the face and other parts at the same position, and improving the strength safety factor at the above position. .

[0015]

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a ship's side longitudinal support showing a scalene angle bar with a bent face according to a first embodiment of the present invention.

[0016]

FIG. 2 is a schematic side view showing a scalene angle bar with a bent face according to the first embodiment of the present invention.

[0017]

FIG. 3 is a sectional view taken along the line AA in FIG. 2;

[0018]

FIG. 4 is a sectional view taken along the line BB in FIG. 2;

[0019]

FIG. 5 is a stress distribution diagram in the scalene angle steel of FIG. 3;

[0020]

FIG. 6 is a schematic side view showing a scalene angle bar with a bent face according to a second embodiment of the present invention.

[0021]

7 is a sectional view taken along the line A'-A' in FIG. 6;

[0022]

8 is a sectional view taken along the line B'-B' in FIG. 6;

[0023]

FIG. 9 is a stress distribution diagram of FIG. 8;

[0024]

FIG. 10 is a perspective view of a ship's side longitudinal support showing a conventional scalene angle steel.

[0025]

FIG. 11 is a cross-sectional view of the scalene angle steel of FIG. 10;

[0026]

FIG. 12 is a cross-sectional view showing forces acting on a conventional scalene angle steel.

[0027]

FIG. 13 is a stress distribution diagram in the scalene angle steel of FIG. 12;

[0028]

[Explanation of symbols]

1　Ship side outer plating 2 Face 3. Web 4 Large bones 5 Stiffener 6 Stiffener position F Shearing force M Torsional moment O centroid Q Shear center P pressure

Claims (1)

[Claims] Claim 1: A scalene angle steel consisting of a web and a face fixed perpendicularly to each other, wherein the web is formed substantially straight and the face is formed so as to have a substantially constant width. A scalene angle steel with a bent face, characterized in that the face is formed to be bent in a plane including the face in order to change the attachment position of the face to the web in the width direction.