JPS58122282A - Steel plate - Google Patents

Abstract

PURPOSE:To obtain a light and strong panel by a method wherein the panel is constituted by fitting reinforcements to the thick parts of a steel plate one surface of which is formed to be flat and the other surface of which is formed to formed to have an intended shape wherein the thickness of the plate is made to be large at prescribed intervals. CONSTITUTION:One surface of a steel plate 4 is formed to be flat, while the other surface thereof is formed to have a plurality of projections 5 which have the same size and are formed monolithically at prescribed intervals, and thus the thickness of the plate is made large at prescribed intervals. On the flat surface 6 of the steel plate 4, a plurality of small ribs 3 are fixed in positions on the opposite side to the projections 5, and moreover, a plurality of large ribs are fixed at right angles to the small ribs 3. The thickness of the flat part of the steel plate 4 and that of the parts of the projections 5 are decided properly in consideration of the maximum vertical load on a panel and a span S betwen the small ribs 3. Although the small ribs 3 are fixed on the surface on the opposite side to the projections 5 in the above constitution, they may be fixed also directly to the projections 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steel plate used for, for example, a ship's outer plate, deck, or wall.

For example, the top plate (inner bottom plate) of a ship's double bottom tank is
As shown in Figures and Figure 2, it has a panel structure in which a plurality of large bones (floors) (2) and stiff bones (3) are fixed to one side of the steel plate. [The required thickness by classification societies for such steel plates subjected to vertical loads such as <The following formula is used as the standard, which assumes that the load at which the first plastic hinge occurs when the strip plate taken from the 37 sides between the small bones of the flannel is subjected to an evenly distributed load is the plastic collapse load of this panel. There is.

Here, t is the thickness of the panel, 8 is the span of the strip, σ is the yield stress of the strip, and W is the collapse load of the (1'I plate.
The bending moment distribution within the elastic region of the strip subjected to a uniformly distributed load as shown in Figure (A) is as shown in Figure 2 (B).
The bending moment is maximum at the point (A) of the small bone (3), and becomes half of it at the point (E>) at the center of the span.
Looking at the plastic strength of the panel, there is a point (A) on the small bone +31 at the center between the large bones (2), a point (O) on the large bone (2) at the center of the small bones (31M (7), and a point on the dog bone i2). n”iJ
(D) It is known that under medium heat, a plastic hinge occurs in the order of the center point (B) between the small bones (3), and as shown by the arrow in Figure 3, the plastic hinge develops and takes a roof-type collapse mode. ing.

The thickness (1) of the steel plate (1) is 13 mm, the span (81) between the large bones (2) is 2115 mm, and the span between the small bones (3) is 8 mm.
) as group 925, and using an elastic-plastic analysis program to examine the occurrence and development of plastic hinges on the surface of the steel plate (1) of the panel, we found that at point (A), a vertical load of approximately 11.4 t/d A plastic hinge is formed, and then at point (0), a load of about 165 t/a is applied, and then at point (0)
B) about 20. It has been confirmed that a plastic hinge occurs under a load of Ot/A, and that the plastic hinge develops in the direction of the arrow in FIG. 3 as the vertical load increases. In this way, the strength of the panel is determined by point (A), and in the conventional configuration, the thickness of the other parts becomes thicker than necessary in order to meet the strength requirements at one point (A), and the entire panel becomes thicker than necessary. There are problems such as an increase in weight.

This invention has been made in view of the above two circumstances, and it is an object of the present invention to provide a steel plate that can be used to construct a lightweight and strong panel.

Embodiments of this invention will be described below with reference to the drawings.

FIG. 4 shows an example of a panel structure using the steel plate (4) according to the present invention. One side of the steel plate (4) is formed flat, and the other side has a plurality of protrusions (5) of the same size integrally formed at regular intervals, and the plate thickness increases at regular intervals. . A plurality of small bones (3) are fixed to the flat surface (6) of the steel plate (4) at positions opposite to the protrusions (5), and a plurality of large bones (not shown) are fixed at right angles to the small bones (3). is fixed to. The thickness of the flat part on both sides of the steel plate (4) and the protrusions (
The thickness of the part 5) is the maximum vertical load acting on the panel,
It is determined as appropriate by considering the span (, ) between the ossicles (3), etc., but for example, the plate thickness at the protrusion (5) is determined by the point (A ) bending t
−≠bending ゛i−mi+ become equal. In this way, small bones (
By increasing the thickness of the parts corresponding to 3), the increase in overall weight is smaller than when the overall thickness is increased, although the same strength is achieved. .

In the above embodiment, there is a small bone (3) on the opposite side of the protrusion (5).
However, the small bones are fixed to the protrusion (5) and the rete is good. Further, in the above embodiment, the ossicles (3) are fixed at all positions corresponding to the protrusions (5), but the ossicles (3) do not necessarily need to be fixed at all these positions.

Furthermore, the shape and size of the protrusion (5) can be arbitrary, and the protrusion (5) can be formed in various sizes on one side of one steel plate, so that the thickness of the protrusion varies depending on the location. It's okay.

Figure 5 shows a panel structure different from the above, and shows a steel plate (
7), relatively large protrusions (8) and relatively small protrusions (9) are formed alternately at regular intervals. A plurality of ossicles (3) are fixed to the flat surface (10) of the steel plate (7) at positions opposite to the large ridges (8), and small ridges (9) are fixed between the ossicles (3). It is located in the center of the span (,). The rest is the same as in the case of FIG. In this way, by increasing the plate thickness at the point (A) on the ossicles (3) and at the point (E) at the center of the span (8) between the ossicles (3), the strength of the panel is further increased.

As a result of analysis using the same elastic-plastic analysis program as above, it was found that by increasing the plate thickness at the position corresponding to the small bones, the collapse load of the panel increased compared to the cases shown in Figures 1 to 3, and the strength increased. (See Figures 6 to 8), the strength can be further increased by increasing the plate thickness at the position corresponding to the ossicles and at the center of the span between the ossicles (see Figures 9 to 11).
(see figure).

That is, in FIGS. 6 to 8, the plate thickness (1) of the double-sided flat JFI portion of the steel plate (11) is 13 mm, and the ridge (12) with a square cross section is formed at a position corresponding to the small bone (3). width ←)
is 200 +++ m, the plate thickness (tl) of this part is 21 doors, and the other conditions are the same as in the case of FIGS. 1 to 3.

As a result of the analysis, a point (D
), a plastic hinge first occurs under a vertical load of approximately 19.9 t/d, and then at point (C) and point (A) 1. In order of point (B), about 21. ．． It was confirmed that a plastic hinge was generated at a load of 9.23.3.27.9 t/i, and that the plastic hinge developed in the direction of the arrow in FIG. 8 as the vertical load increased.

In addition, in FIGS. 9 to 11, the position of the steel plate (13) corresponding to the ossicles (3) and the span (S) between the ossicles (3) are also shown.
) Width of the protrusion (14) with a rectangular cross section formed in the center of ) ←)
is 2QO++++ns, and the plate thickness (tl) of this part is 21 mm, and the other conditions are the same as in the case of FIGS. 6 to 8. As a result of the analysis, first, at point (A), approximately 23.
A plastic hinge is formed under a vertical load of Ot/d, and then the point (C)
, Point (E) and point (D) at the boundary between the ridge (14) at the center of the span (s) between the small bones (3) and the flat portion on both sides at the center of the span (sl) between the large bones (2). '27.0 respectively
%33.0.35. It was confirmed that a plastic hinge was generated under a load of Ot/d, and that the plastic hinge developed in the direction of the arrow in FIG. 11 as the vertical load increased.

As described above, according to the steel plate of the present invention, one side is formed flat and the other side is formed in a concave and convex shape so that the plate thickness increases at regular intervals, so that the plate thickness increases. By inserting several reinforcing materials in the necessary parts of the parts, it is possible to construct a lightweight and strong panel, which has the same great strength as if the overall board thickness was increased, and compared to the conventional one. This has the advantage that the overall weight increase is smaller than that of a steel plate with a uniformly large overall thickness, and the reinforcing material attached to the steel plate can be small.

[Brief explanation of the drawing]

1 to 3 show a conventional example, FIG. 1 is a partial plan view of the panel, FIG. 2 is an enlarged sectional view taken along line II-II in FIG. 1 and its bending moment diagram, and FIG. Fig. 4 is an enlarged view of part a showing the results of analysis of the occurrence and development of plastic hinges on the surface of a steel plate using the elastic-plasticity 1 analysis program; Fig. 4 is a drawing showing an example of the invention;
b) Equivalent drawings: FIG. 5 is a drawing equivalent to FIG. 4 showing another embodiment of the present invention; FIGS. 6, 7, and 8 show still other embodiments of the present invention; Figure 6 is a partially enlarged plan view of the panel, Figure 7 is a drawing equivalent to Figure 3, and Figures 9, 10, and 11 showing the results of analysis using the Elastoplastic program described in Section 6. These are drawings showing still other embodiments of the present invention and corresponding to FIGS. 6, 7, 6L, and 8, respectively. (4) (71(Ill (131... steel plate, +
51 +8+ +91 +12) +14)...
Projection, f(3) flol...Flat surface. 2 Patent Applicants [1 Ritsusensen Co., Ltd. 15゛"A1"''', Ar ff4 2 1JI
“ 1 other 4 people March 26, 1982 1. Indication of the incident 1981 Toku W'I Drunk I No. 2952
82. Title of the invention Metal plate 3. Relationship with the case of the person making the amendment Patent applicant address 1-6-14 Edobori, Nishi-ku, Osaka Name 8
Name (511) Hitachi Zosen Co., Ltd. 4, Agent Address 6, Tr. 57, Unagidani Nishinocho, Minami-ku, Osaka City
Inaba Building 6th floor Telephone Osaka (252) 2436/438
7 Name 160g7) Buri Tokishimoto Einosuke 6, 1F
Uchitani 111 The scope of the claims will be amended as shown in the appendix. (2) The name of the invention "steel plate" on page 1, line 3 of the specification is corrected to "metal plate." In the 10th line of the same page, after "steel plate", add "such as kinkyo plate". (3) Same book, page 4, number 8? ′]′ Correct “steel plate” to “metal plate”. Add ``(metal plate)'' after ``steel plate'' in No. 11h' of the same page. (4) The following sentence is added between lines 5 and 6 on page 9 of the same book. ``This invention is applicable only to steel plates <but can be applied to all metal plates such as aluminum plates.'' In the 6th and 15th lines of the same page, the words ``steel plate'' in the two places are corrected to ``metal plate.'' (5) Add "(金-板)" after "rl board" on page 11, line 3 of the same book. What is claimed above: A metal woven plate characterized in that one side is flat and the other side is uneven so that the plate thickness increases at regular intervals.

Claims (1)

[Claims] A steel plate characterized in that one side is flat and the other side is uneven so that the plate thickness increases at regular intervals.