JPS6034554Y2 - semi-submersible catamaran - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a semi-submersible catamaran in which a pair of left and right lower hulls below the water surface are connected by a deck section above the water surface via struts.

In general, semi-submersible catamarans are strongly required to have lightweight hulls in order to ensure high-speed performance.

In conventional designs, plate structures such as decks and outer panels have the strength to withstand out-of-plane distributed loads such as water pressure, and also function as large aggregate flange plates to prevent bending deformation of the hull. Therefore, the plate thickness is determined so that it has the strength to withstand the in-plane load in that case.

The deflection of the plate caused by excessive out-of-plane loads significantly reduces the strength of the plate against in-plane loads.
The plate thickness is calculated to prevent large plate deflections.

In this case, the plate becomes thicker than necessary in terms of breaking strength against out-of-plane distributed loads such as water pressure.

Therefore, if steel were used, the weight of the ship would be too heavy, so conventionally, attempts were made to reduce the weight by using aluminum alloy materials.

However, aluminum alloy materials have a problem in that material costs, processing costs, etc. are higher than steel materials.

This invention aims to reduce costs by using steel plates.
By changing the design concept for conventional plate structures and creating a structure that has two separate strengths: strength against out-of-plane distributed loads such as water pressure, and strength against in-plane loads due to bending deformation of the ship, etc. The purpose is to provide a semi-submersible catamaran whose weight can be significantly reduced.

For this reason, the semi-submersible catamaran of the present invention consists of a lower hull arranged in pairs on the left and right under the water surface, struts extending upward from the lower hull through the water surface, and these left and right struts. and a deck section that connects them above the water surface,
A longitudinal girder is provided to connect the upper deck and lower skin of this deck section, and strip plates are horizontally interposed between the upper deck and lower skin and the upper and lower ends of the stringer. It is characterized by the fact that the band plate is made of a thicker plate than the upper deck and lower outer plate.

Below, a semi-submersible catamaran as an embodiment of the present invention will be explained with reference to the drawings. Figure 1 is a cross-sectional view of the hull;
FIG. 2 is an enlarged partial sectional view of the section ``■'' in FIG. 1.

As shown in these figures, lower hulls 1 that account for most of the buoyancy are arranged in pairs on the left and right below the water surface W, and struts 2 extend upward from each lower hull 1 through the water surface W. It is provided.

A deck portion 3 is provided that connects the upper ends of the left and right struts 2 above the water surface W, and this deck portion 3 is an extremely important portion in terms of hull strength.

By the way, in the semi-submersible catamaran of the present invention, the longitudinal girder 6 as a large aggregate that connects the upper deck 4 and the lower skin 6 of the deck section 3 is as shown in FIG. Upper and lower ends of upper deck 4
and the lower outer plate 5, respectively, by welding via a band plate 7.

Out-of-plane loads due to cargo, water pressure, etc. act on the upper deck 4 and the lower skin 5, and as a result, the longitudinal girders 6 are bent, and this bending deformation generates in-plane loads.

In the structure according to the present invention, the structural members that share the out-of-plane load and the structural members that share the in-plane load are separated, the former being the upper deck 4 and the lower skin 5, and the latter being the strip plate 7.

In the case of conventional longitudinal girders, there was no band plate 7 and the girder plates were directly joined to the upper deck 4 and the lower skin plate 5, so the upper deck 4
and the lower skin plate 5 shared both the out-of-plane load and the in-plane load, but large deflection of the upper deck or lower skin plate in the out-of-plane direction would significantly reduce the in-plane strength of the plate. , cannot tolerate large out-of-plane deflections.

If the strip plate 7 is provided horizontally and is thicker than the upper deck 4 and the lower skin 5, as in the structure of the present invention, and the in-plane load is shared by it, the upper deck 4 and the lower skin 5 will be Since it is only necessary to share the out-of-plane load, it is possible to tolerate greater out-of-plane deflection compared to conventional structures.As a result, the thickness of the upper deck 4 and lower skin 5 is reduced, and the band The weight of the upper deck 4 and the lower skin 5 is reduced by more than the increase in weight due to the provision of the structure 7, and the overall weight is reduced.

In addition, in conventional structures, in order to maintain the required in-plane strength, it was necessary to suppress the out-of-plane deflection of the plate caused by welding, etc. to a predetermined value or less, but with the structure of the present invention, this can be suppressed. This also has the advantage of making the work easier because the problem is alleviated.

[Brief explanation of drawings]

The figures show a semi-submersible catamaran as an embodiment of the present invention. Figure 1 is a cross-sectional view of the hull, and Figure 2 is a
It is a partial sectional view which expands and shows a part. 1... Lower hull, 2... Strut, 3... Deck section, 4... Upper deck, 5
...Lower skin, 6...Longitudinal girder, 7...
...Strip plate, W...Water surface.

Claims (1)

[Scope of utility model registration request] This deck includes a lower hull arranged in pairs on the left and right under the water surface, struts extending upward from the lower hull through the water surface, and a deck section connecting these left and right struts above the water surface. A longitudinal girder is provided to connect the upper deck and lower skin in the section, and strips are horizontally inserted between the upper deck and lower skin and the upper and lower ends of the stringer, respectively. , a semi-submersible catamaran, characterized in that the band plate is formed of a plate material thicker than the above-mentioned upper deck and lower outer plate.