JPS6231359Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a panel structure used for, for example, the outer panel, deck, bulkhead, etc. of a ship.

Prior art and its problems For example, the top plate (inner bottom plate) of a double bottom tank of a ship, as shown in Figures 1 and 2,
It has a panel structure in which a plurality of large bones (floors) 2 and small bones (stiffeners) 3 are fixed to one side of a steel plate 1. The required thickness by classification societies for such steel plates, which are subjected to vertical loads such as water pressure, is determined based primarily on the plastic collapse of panels whose periphery is fixed with small and large bones. In other words, the load at which the first plastic hinge is generated when the short side of the panel between the small bones of the panel subjected to the vertical load is subjected to an evenly distributed load is considered as the plastic collapse load of this panel. The formula is the standard.

Here, t is the thickness of the panel, s is the span of the strip, σ is the yield stress of the strip, and w is the collapse load of the strip. The bending moment distribution within the elastic region of the strip subjected to a uniformly distributed load as shown in Figure 2A is as shown in Figure 2B, and the bending moment is at point A on the small bone 3.
It reaches a maximum at point B at the center of the span, and becomes half of it at point B at the center of the span. On the other hand, regarding the plastic strength of the panel, point A on the ossicle 3 at the center between the large bones 2, point C on the large bone 2 at the center between the 3 bones, and point C on the large bone 2 at the center between the 2 large bones and the center between the 3 small bones. It is known that a plastic hinge occurs in the order of point B, and as shown by the arrow in FIG. 3, the plastic hinge develops and takes a roof-type collapse mode. The thickness t of the steel plate 1 is 13 mm, the span s1 between the large bones 2 is 2115 mm, the span s between the small bones 3 is 925 mm, and the steel plate 1 of the panel is
As a result of examining the occurrence and development of plastic hinges on the surface using an elastic-plastic analysis program, we found that first, a plastic hinge occurs at point A under a vertical load of approximately 11.4t/ ^m2 , and then at point C, approximately
With a load of 16.5t/ ^m2 , approximately
It has been confirmed that a plastic hinge occurs at a load of 20.0t/m ² and that the plastic hinge develops in the direction of the arrow in Figure 3 as the vertical load increases. In this way, the strength of the panel is determined at point A, and when constructing a panel using steel plates with uniform thickness as in the past, other parts must be adjusted to meet the strength requirements at point A. There are problems in that the board becomes thicker than necessary and the weight of the entire panel increases.

The purpose of this invention is to solve the above problems and provide a lightweight and strong panel structure.

Means for Solving the Problems In the panel structure according to this invention, a plurality of small bones are fixed to one side of a metal plate, and a protrusion is formed on at least one side of the metal plate at a position corresponding to the small bones and at the center of the span between the small bones. As a whole, protrusions are formed on both sides, and the thickness of the metal plate is thicker at the protrusions.

The protrusions may be formed only on one side of all parts. In this case, the arrangement of the protrusions formed on one surface and the protrusions formed on the other surface is arbitrary, and they may be arranged alternately or every multiple rows. be. Further, the protrusions may be formed on both sides of all parts. Furthermore, a single metal plate may have a portion where protrusions are formed on both sides and a portion where protrusions are formed only on one side, and may be arbitrarily arranged. The shape and size of the protrusions are arbitrary, and it is not necessary that the thickness of the protrusions be equal in all parts, nor is it necessary that the mutual spacing between the protrusions be equal in all parts. Furthermore, this invention can be applied to panel structures using not only steel plates but also any metal plates such as aluminum plates.

Function: By forming protrusions on the metal plate at the positions corresponding to the small bones and at the center of the span between the small bones and increasing the plate thickness, the collapse load of the panel increases and its strength increases, and the overall strength of the metal plate increases. Compared to a case where the plate thickness is uniformly increased, the overall weight increase is small even though the plate has the same great strength.

Embodiment FIGS. 4 and 5 show an embodiment of a panel structure using a steel plate (metal plate) 10.

The steel plate 10 has protrusions 11 with a rectangular cross section integrally formed on one surface (upper surface) and protrusions 11 with a rectangular cross section integrally formed on the other surface (lower surface) alternately at regular intervals. The plate thickness increases at regular intervals. That is, a plurality of protrusions 11 of the same size are formed at regular intervals on the upper surface of the steel plate 10, and a protrusion 11 of the same size is formed on the lower surface of the center between them. A plurality of small bones 3 are fixed to the lower surface of the steel plate 10 in a portion where a protrusion 11 is formed on the upper surface, and the protrusion 11 formed on the lower surface is located at the center of the span s between the small bones 3. Furthermore, a plurality of large bones 2 are fixed to the lower surface of the steel plate 10 at right angles to small bones 3. The plate thickness of the portion of the steel plate 10 with the protrusions 11 and the plate thickness of the double-sided flat portion without the protrusions 11 are appropriately determined in consideration of the maximum vertical load acting on the panel, the span s between the small bones 3, etc. In this way, by increasing the plate thickness at the position corresponding to the ossicles 3 and at the center of the span s between the ossicles 3, an equivalent large strength can be achieved compared to a case where the entire plate thickness is uniformly increased. Despite this, the overall weight increase is small.

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 ossicles and at the center of the span between the ossicles, the collapse load of the panel was reduced compared to the cases shown in Figures 1 to 3. It was confirmed that the strength increases as the That is, in FIGS. 4 to 6, the thickness t of the flat portion on both sides of the steel plate 10 is 13 mm, the width b of the protrusion 11 is 200 mm,
The plate thickness t1 of the protrusion 11 is 21 mm, and the other conditions are the same as in the case of FIGS. 1 to 3. As a result of the analysis, first, at point A, approximately 23.0t/m ²
A plastic hinge occurs due to the vertical load of , and at the point C, the span s between the small bones 3 is
Point E at the boundary between the central protrusion 11 and the flat portion on both sides, and point D at the boundary between the protrusion 11 on the small bone 3 and the flat portion on both sides at the center of the span s1 between the large bones 2. It was confirmed that a plastic hinge was generated at loads of 27.0, 33.0, and 35.0 t/ ^m2 , and that the plastic hinge developed in the direction of the arrow in Figure 6 as the vertical load increased.

For comparison, a panel (comparative example) in which the protrusions 11 were formed only at positions corresponding to the small bones 3 of the steel plate 10 was prepared, and an analysis was performed using the same elastic-plastic analysis program as described above. As a result, the comparative example has an increased collapse load and strength of the panel compared to the conventional example shown in Figures 1 to 3, but compared to the example of this invention shown in Figures 4 to 6. It was confirmed that the strength was small. That is, the small bones 3 of the steel plate 10
It was confirmed that by not only forming the protrusion 11 at the position corresponding to the ridge 11 but also forming the ridge 11 at the center of the span between the small bones 3, the collapse load of the panel was further increased and the strength was increased. .

FIG. 7 shows another embodiment of a panel structure using the steel plate 10 described above, in which a plurality of small bones 3 are attached to the steel plate 10.
0 is fixed to the lower surface of the protrusion 11 formed on the lower surface. The rest is the same as in FIGS. 4 and 5.

FIG. 8 shows an embodiment of a panel structure using a steel plate 12 different from that described above, in which protrusions 13 and 14 are formed on both upper and lower surfaces of the steel plate 12 at regular intervals. A plurality of small bones 15 are fixed to the lower surface of the ridges 14 formed on the lower surface of the steel plate 12 in every other row, and a plurality of large bones (not shown) are fixed to the lower surface of the steel plate 12 at right angles to the small bones 15. ing.

FIG. 9 further shows an embodiment of a panel structure using a steel plate 16 different from that described above. Projections 17 and 18 are formed on the upper and lower surfaces of the steel plate 16 at regular intervals, and a projection 19 is formed on the upper surface of the center between these.
is formed. A plurality of small bones 20 are fixed to the lower surface of the protrusion 18 formed on the lower surface of the steel plate 16, and a plurality of large bones (not shown) are fixed to the lower surface of the steel plate 16.
is fixed at right angles to the ossicles 20.

Effects of the invention According to the panel structure of this invention, protrusions are formed at positions corresponding to the small bones of the metal plate and at the center of the span between the small bones, making the plate thicker, making it possible to create a lightweight and strong panel. It has the same great strength as when the overall plate thickness is increased, and the overall weight increase is smaller than the conventional one where the overall plate thickness is uniformly increased. I'll try it.

[Brief explanation of the drawing]

Fig. 1 to Fig. 3 show a conventional example, Fig. 1 is a partial plan view of a panel using a steel plate, Fig. 2 is an enlarged sectional view along the line of Fig. 1 and its bending moment diagram, and Fig. 3 is a partial plan view of a panel using a steel plate. Fig. 1 is an enlarged view of part a showing the results of analysis using an elastic-plastic analysis program on the occurrence and development of plastic hinges on the surface of a steel plate, and Figs. 4 to 6 show one embodiment of this invention. , Figure 4 is a partial plan view of a panel using steel plates,
Figure 5 is a sectional view taken along the line shown in Figure 4, and Figure 6 is a cross-sectional view along line 4.
A drawing corresponding to Fig. 3 showing the enlarged part of Fig. a and the results of analysis using the above-mentioned elastic-plastic analysis program, and Fig. 7 a drawing corresponding to Fig. 5 showing another example of the panel using the above-mentioned steel plate. , FIG. 8 and FIG. 9 are drawings corresponding to FIG. 5 showing two embodiments different from the above. 10, 12, 16... steel plate (metal plate), 11,
13, 14, 17, 18, 19...projections.

Claims (1)

[Scope of utility model registration request] A plurality of ossicles are fixed to one side of the metal plate, and ridges are formed on at least one side of the metal plate at positions corresponding to the ossicles and at the center of the span between the ossicles, so that ridges are formed on both sides as a whole, A panel structure in which the thickness of the metal plate is thicker at the ridges.